2004 RCSB 4x4 - The Mail Truck

[INW-Iron-Steel]

This is my much beloved 2004 Sierra 1500. I have modded this truck a lot over the years. I'll post the mods up in this build thread, as well as future modifications I have in mind. My dad originally bought it and we built it up to fulfill his dream of a 4wd el camino. I officially purchased it from him about 10 years ago after my little sister totaled my parent's only car under warranty. They're getting old and like to have one car under warranty for road trips and such. They were going through some financial troubles and were going to need to sell the truck to justify undoing my sister's fine work. I emptied my checking account and sold my daily at the time, walked up to them and handed them literally everything I had. I think I said, "I know it's not what it's worth, and I'll get you more when I can, BUT DONT SELL THE TRUCK!" Best decision I've ever made.

Some details on the truck: RCSB 4x4 WT (crank windows, rubber floors). 4.8/4l60/8.6 (3.73 gears). Floor shift NP261. I think the official numbers on the drop are 2" front and 3-4" rear. It is (or was) perfectly level when we first lowered it. The springs have since sagged A LOT. Kooks LT headers and high flow catted y-pipe, with a Pypes Vilolator cat-back system. That's pretty much how it stayed when the old man owned it.

Here are some pictures of the original build on the truck. I think these pictures are from the first day I owned it. (Notice the different tires. First thing I did was replace the Nitto H/Ts with some Cooper A/T3s).





Oh, and some carnage from the malibu!


She swerved to miss a deer and contacted a steel I-beam mounted mailbox with the R-front corner. You can see the 04 was present as the flat bed yarded the malibu up off the street

 

[INW-Iron-Steel]

I am going to try to chronicle the mods and pictures in a a past-to-present configuration. It is going to take me some time to go through old pictures, but I will get them posted up here when I figure out the correct order.

Oh, also. I've owned this rig for over 10 years now, but only recently named it. I swapped out the roudy muffler for a Walker OE off a 4.3 astro. The combo of the headers with this muffler gives a very unique (and weird) exhaust note. It sounds like a pissed off UPS truck under hard acceleration. It's white SO... Mail Truck! I'm not hauling ass, I'm hauling the mail!

Anyway, stay tuned for more!

 

[INW-Iron-Steel]

At some point my old man painted the work truck front bumper and chrome all flat black (while I owned it, without asking me). I was storing it at their house one summer while I took my fox-body back to Seattle in college. I remember him telling me "I did something I think you're really gonna like." I showed up and saw the front bumper painted, and literally s*** my pants (not in a good way). I hate it, and I told him that day I hated it. I loved the unassuming look of the work truck front clip, and to me the flat black just makes it look... IDK, I just don't like it. This has been my go to vehicle for years, and the blacked out front has stayed to this day. I've never had the time or energy to replace it, but I would really love to find an unmolested work truck front end to bring it back to its' former glory.

Here is a picture gassing up at the top of Snoqualmie pass sometime when I was in college, probably headed home for Thanksgiving. Not sure why I took this photo, but to this day I love seeing the Cascades peeking out in the background.

 

[INW-Iron-Steel]

Already out of order but I found this gem while digging through photos.

Here's the original 4.8 relegated to the corner of the shop, waiting for me to resurrect it for something (I have a wild plan, but we'll get to that later). It was plagued with the 'castech crack'. If you're losing coolant but have no leaks, I have some bad news for you... Drain the oil and proceed to cry a little as you debate whether to rebuild the top end or just get a whole new engine. This one was ran long enough with coolant as lubrication that we killed at least a few lifters (and potentially more, I haven't tore it all the way down yet).

Edit- This original 4.8 was pulled at 175,000 miles. I swapped it out with a 90,000 mile 4.8 from a 99 model year courtesy of our local junkyard. It was cheaper than the newer engines and had better vitals. I think I scored it for $750 with a warranty. So, the replacement 4.8 has nearly the same mileage on it now as the original did when it got pulled.



Around this time is when I rebuilt the front steering/suspension for the first time (back when Moog was still good)

I slit the pitman arm right between the splines without touching the shaft on the steering box... This was a "oh, you're coming off" moment after I broke 2 pitman arm pullers. How good are you with the cutoff wheel?

 

[INW-Iron-Steel]

Next, we start getting into the mods! As I owned it longer and the miles racked up, there were some general wear items that needed addressing. But first, I will say I LOVE factory upgrades. I like to replace worn out parts with better parts when able. One of the best upgrades you can do to a GMT800 (in my opinion) is to upgrade the fronts brakes to GMT900 parts. GM, being as lazy as they are, used the same spindle/knuckle mounting on both platforms. What that means for the average guy: When buying parts for a brake job, tell the parts counter guy you drive a GMT900. I think I am running 2008-ish Tahoe front brakes. As long as you get the calipers with mounting brackets, the matched pads, and the bigger rotors, it will all literally bolt right on.

*Pay attention here if you are doing this mod, I don't want you to be upset with me later on.*

If you are running 16 inch wheels, forget about this mod until you are willing to run 17s. The rotors are 1" larger in diameter, which pushed the caliper further out (why you need the caliper mounting bracket as well). Also, GM used quite a few different caliper/pad combos in the same model year on these things. So be diligent when matching parts. You can find the caliper part number right on the caliper itself, and most brake pad manufacturers will tell you what pads to run with which caliper. Here are some photos with the 17s on the truck. (Some of you may notice these look the same as the wheels that are now on the 93 Burb... because they are the same wheels, just recycled on that build. I think they're on the 4th or 5th set of tires now. If Level 8 made these in an 18, I would buy them in a heartbeat).





The photo above was originally taken to depict the issues with trying to run 17s on drop spindles that explicitly say "for use with 18 inch wheels only"... Ball joint nut grounded down and wheel weights placed accordingly. I always had to specify to tire techs not to use the stick on wheel weights, but to use the tap on weights on the inside lip of the wheel. It was fun to rotate the tires and find out they didn't listen, punt off the weights on the way back to the tire shop, and have them redo their work properly... So much time wasted.

 

[INW-Iron-Steel]

Jumping ahead just a little bit, I wanted to show off my cluster. Again, I LOVE factory upgrades. The 2500 trucks got a transmission temp gauge, while the 1500s did not. The computer already sees the transmission temp from the 4l60, so just swapping in a 2500 cluster gets you a temp gauge. So, when my stepper motors started to fail and told me I had ALL the oil pressures, I sourced a 2500 cluster.

*I recomend finding a reputable rebuilder who knows what they are doing. I got mine from a guy on ebay (I will try to find his store and update this post) who modifies and customizes clusters exclusively for GMT800s. He will ask you for your vin and mileage to make sure it is programmed correctly to interface with your exact vehicle, plugs in, and works flawlessly.

Side note, I don't think I ordered it with custom blue backlights, but I am glad it came that way. It gives my truck a really cool look at night, and it perfectly matches my alpine head-unit. I still have the black gauges with while lettering, so it looks completely stock during the day, but it really pops at night.

 

[ORVietVet]

"Cluster Porn"

 

[INW-Iron-Steel]

"Cluster Porn"

I apologize in advance if this accidentally makes you "excited"

 

[ORVietVet]

I apologize in advance if this accidentally makes you "excited"

No problem at all. I got some 2-3 days ago on my 2005 Tahoe Z71, in the driveway before I went to eat tacos with my AL friends.

 

[INW-Iron-Steel]

No problem at all. I got some 2-3 days ago on my 2005 Tahoe Z71, in the driveway before I went to eat tacos with my AL friends.

View attachment 2021

OO! I like those A LOT! Is that a white needle with silver in the center? Or all silver? That looks GOOD!!!

 

[ORVietVet]

OO! I like those A LOT! Is that a white needle with silver in the center? Or all silver? That looks GOOD!!!

All silver, just like the Tahoe. the rest is stock. I stayed with the stock needles on the 2004 Silverado.

 

[someotherguy]

Next, we start getting into the mods! As I owned it longer and the miles racked up, there were some general wear items that needed addressing. But first, I will say I LOVE factory upgrades. I like to replace worn out parts with better parts when able. One of the best upgrades you can do to a GMT800 (in my opinion) is to upgrade the fronts brakes to GMT900 parts. GM, being as lazy as they are, used the same spindle/knuckle mounting on both platforms. What that means for the average guy: When buying parts for a brake job, tell the parts counter guy you drive a GMT900. I think I am running 2008-ish Tahoe front brakes. As long as you get the calipers with mounting brackets, the matched pads, and the bigger rotors, it will all literally bolt right on.

*Pay attention here if you are doing this mod, I don't want you to be upset with me later on.*

If you are running 16 inch wheels, forget about this mod until you are willing to run 17s. The rotors are 1" larger in diameter, which pushed the caliper further out (why you need the caliper mounting bracket as well). Also, GM used quite a few different caliper/pad combos in the same model year on these things. So be diligent when matching parts. You can find the caliper part number right on the caliper itself, and most brake pad manufacturers will tell you what pads to run with which caliper. Here are some photos with the 17s on the truck. (Some of you may notice these look the same as the wheels that are now on the 93 Burb... because they are the same wheels, just recycled on that build. I think they're on the 4th or 5th set of tires now. If Level 8 made these in an 18, I would buy them in a heartbeat).

View attachment 2012

View attachment 2013

The photo above was originally taken to depict the issues with trying to run 17s on drop spindles that explicitly say "for use with 18 inch wheels only"... Ball joint nut grounded down and wheel weights placed accordingly. I always had to specify to tire techs not to use the stick on wheel weights, but to use the tap on weights on the inside lip of the wheel. It was fun to rotate the tires and find out they didn't listen, punt off the weights on the way back to the tire shop, and have them redo their work properly... So much time wasted.

Pretty sure those are the same brakes stock on our '06 SS, if you don't wanna have to tell them you have a GMT900 just to get brakes. I mean, the shame of claiming a GMT900.

Pic is from when I did upper/lower ball joints on the truck but should give a nice view of the 2 piston caliper and 13" rotor. The SS comes with 20's so no clearance issues.



Richard

 

[INW-Iron-Steel]

Pretty sure those are the same brakes stock on our '06 SS, if you don't wanna have to tell them you have a GMT900 just to get brakes. I mean, the shame of claiming a GMT900.

HAHA! Good Day! Now I don't have to accept that shame of the GMT900 when ordering brakes!

I have a set of brake pads for it sitting in the garage. I will take a picture of the part# later in the week when I am sorting through some things. Maybe we can confirm they are indeed the same. It was always my understanding that GM didn't spec 17" wheels on all of the trims until the GMT900. So, GMT800 originally spec'd with 16's had the smaller brakes. I wonder how many GMT800s got the bigger brakes?

I know the Suburban/Tahoe rear calipers are bigger than the low GVWR single piston calipers on my 04 WT. The next time I do rear brakes I am buying suburban stuff.

 

[INW-Iron-Steel]

I am doing a really bad job of posting this in chronological order! So, we're goin back in time to before the blue gauges and around when I did the big brake upgrade in an apartment garage in college...

For the next few years the truck was just driven! I can't find any pictures of it. I was living in downtown Seattle circa 2018 and I didn't use my car much. I was pretty much parked in a garage unless I needed to leave the city. I have pictures of other cars around that time, but none of the 04. I think I considered selling it for a bit around this time period. It was pretty worn out, and not quite old enough to be cool. I had taken it from 175K to around 220K in just a few years. The 4l60 was doing 220K mile 4l60 things, the front end was worn out again, it needed new tires (Those Coopers wore like iron looking back on it), the shocks were blown out... It needed some love!

I am making this post in case I find any of the pictures of the truck from this time period. I know they are out there somewhere.

Edit: Found a couple. I still know there's more

(That's not fog setting in, that's smoke. The fires the last 10 years have been bad)

 

[ORVietVet]

HAHA! Good Day! Now I don't have to accept that shame of the GMT900 when ordering brakes!

I have a set of brake pads for it sitting in the garage. I will take a picture of the part# later in the week when I am sorting through some things. Maybe we can confirm they are indeed the same. It was always my understanding that GM didn't spec 17" wheels on all of the trims until the GMT900. So, GMT800 originally spec'd with 16's had the smaller brakes. I wonder how many GMT800s got the bigger brakes?

I know the Suburban/Tahoe rear calipers are bigger than the low GVWR single piston calipers on my 04 WT. The next time I do rear brakes I am buying suburban stuff.

My 2005 Tahoe Z71 came with 17" wheels. I have done brakes front and rear on it but just went by application and did not pay attention. I have been working on a friend's 2005 Tahoe LS and know it will likely need brakes come summer or fall. I guess I can find my RA paperwork and compare. I have not paid attention and maybe her LS has 16" wheels?

 

[INW-Iron-Steel]

I was at a crossroads with the truck. Fix the minor things and sell it to buy something new, or bring it back to life. I chose to give it some much needed love. As I entered my career I decided that I would replace every part of the drivetrain to make it bulletproof again.

That started with the front suspension. Below is a picture mid-rebuild. I had a shop-press at this point, so the upper arms were probably over on the press getting new bushings and ball-joints. You can see the drop spindles in these pictures. I cannot remember what brand they are, and I do not know if they're still made. The picture of the spindle without the hub is several months after I replaced all the front suspension. I had changed the hubs back when my dad owned it, so I figured they were good. Those 1A-auto hubs lasted approx 155K to 230K (guessing based on looking at mileage, registrations, and pictures).

-Edit: I forgot to mention along with the front suspension I changed the steering box (Blue Top), steering shaft (GM genuine) and green bushing thing way up in the column (I can't remember the technical term). I wanted every component from the steering wheel down to be new.

No... that's definitely not a pipe for extra leverage on the end of the breaker bar...


I used Mevotech Supreme suspension components, and Mevotech Supreme hubs later on. Having heard decent things about them, and with MOOG now junk, I figured I would try the stuff. The only non-Mevotech part was the lower ball-joints. RA accidentally sent me 1 lower and 3 uppers (good thing actually, I damaged one upper while pressing it in). I opted for the refund and found a different pair... a decently priced set of Dorman 'Rugged Duty' lower ball-joints.

I'll admit, I fell for the marketing hype. But, these might be the only good parts I have ever bought from Dorman.


There's some carnage here too. I broke that bolt for the brake line after I ordered ball-joints and had decided not to just replace the whole upper arms. Not to be defeated by my own crap luck, I drilled and tapped a hole just far enough forward for the metal tab on the brake line to sit flush on the control arm.

 

[INW-Iron-Steel]

And, like any refresh, a new set of wheels. I had decided I didn't want to cut up the ball-joints this time. The tires are 285/60/18s on what I think are 10 wide Ion's with 5 inches of backspacing. They are wide, but I only rub the inner fenders at absolute full lock.

Picking them up from being mounted/balanced


I was also helping my future wife fix up her 93 burb and thought the black 5-spokes would look good on it. It needed new tires bad. If I am remembering correctly, it had the early GMT800 Silverado 16s on it. I didn't think it looked right. I "sold" her my wheels and tires for $25 a wheel, and the old coopers had about one winter left in them.



While working on the suspension I realized the brakes were pretty worn, so I ordered up some new pads/rotors/hardware for all four corners. They didn't come in time for the alignment I had scheduled, so I just took the truck to get an alignment with my fresh wheels. The first shop didn't get it right. They actually forgot to fully torque the upper control arm bolts, causing it to come out of alignment rather quickly on our pothole ridden streets. I dropped it off at a shop down the street from where I was working the next morning... and this is where it turned into a real debacle. I appreciate their diligence and willingness to include a free inspection, but I wish they would have asked first. I would have told them to save their time and just do the alignment. They 'discovered' a frozen caliper after disassembling my rear-brakes. One of the pads was almost metal to metal (I knew this) and they wanted to do my brakes. I kindly told them I had brakes on the way for the truck when they called telling me this. I'm not going to lie, I was a little confused as to why they were looking at my rear brakes when I had dropped it off for an alignment. Regardless, they re-assembled it as-was. But the act of freeing that pad allowed for some destruction. This is my brand new wheel after driving about 7 miles home...



They were not very apologetic, so I make sure to guide all my friends/family elsewhere. I never got all the metal off. It was cold outside so the hot metal from the brakes rapidly cooled when it hit the wheel. The finish was damaged. In the spots where I did get it off, they were dull and no longer glossy (I actually tried bringing it in the bathtub so it was warmer and i could use hot water). I gave up and ordered a new wheel. I figured it would be better to let them fade as a set. I kept the 'orange' one in case I severely damage a wheel and they stop making them. If you look closely at that corner of the truck, you can still see little tiny orange specks in the clearcoat. I've gotten over it, the 20 year old paint is certainly not perfect.

Here's a pic from when it was all back together. I think it does a good job of showing the offset with the tires just barely sticking out past the fenders. But it also shows the mail truck actually performing its' duties!

 

[someotherguy]

HAHA! Good Day! Now I don't have to accept that shame of the GMT900 when ordering brakes!

I have a set of brake pads for it sitting in the garage. I will take a picture of the part# later in the week when I am sorting through some things. Maybe we can confirm they are indeed the same. It was always my understanding that GM didn't spec 17" wheels on all of the trims until the GMT900. So, GMT800 originally spec'd with 16's had the smaller brakes. I wonder how many GMT800s got the bigger brakes?

I know the Suburban/Tahoe rear calipers are bigger than the low GVWR single piston calipers on my 04 WT. The next time I do rear brakes I am buying suburban stuff.

With the Silverado SS it'll be all 2006, and possibly 2005 though 2005 had AWD and RWD choices. The dual piston caliper has been discussed a bunch on the SS forums typically referred to as upgrading to the "Tahoe brakes" - before they were available on the SS. I'd be really surprised if the Suburbans didn't have them, too.

If you look up any of the GMT800 applications on Rock you'll see where some have both listings in the brake section - single piston or dual piston caliper for the front.

Now if you really wanna get froggy, any of the brake upgrades from GMT800 on up to the K2XX series and maybe even beyond that can be used. Some of them are direct-bolt, some of them take some very minor adapting like spacing the rotor out very slightly with some washers. Of course wheel compatibility become an issue as the rotor gets larger. There's also wheel depth compatibility issues depending on caliper, as some guys have been adapting the 4 piston caliper that has that big rib in the middle of the casting.

You could go really wild and get the GMPP 6 piston Brembo caliper with the 16" rotor upgrade.. last time I looked it was $2300+

Richard

 

[someotherguy]

I was at a crossroads with the truck. Fix the minor things and sell it to buy something new, or bring it back to life. I chose to give it some much needed love. As I entered my career I decided that I would replace every part of the drivetrain to make it bulletproof again.

That started with the front suspension. Below is a picture mid-rebuild. I had a shop-press at this point, so the upper arms were probably over on the press getting new bushings and ball-joints. You can see the drop spindles in these pictures. I cannot remember what brand they are, and I do not know if they're still made. The picture of the spindle without the hub is several months after I replaced all the front suspension. I had changed the hubs back when my dad owned it, so I figured they were good. Those 1A-auto hubs lasted approx 155K to 230K (guessing based on looking at mileage, registrations, and pictures).

No... that's definitely not a pipe for extra leverage on the end of the breaker bar...
View attachment 2069
View attachment 2073View attachment 2074
I used Mevotech Supreme suspension components, and Mevotech Supreme hubs later on. Having heard decent things about them, and with MOOG now junk, I figured I would try the stuff. The only non-Mevotech part was the lower ball-joints. RA accidentally sent me 1 lower and 3 uppers (good thing actually, I damaged one upper while pressing it in). I opted for the refund and found a different pair... a decently priced set of Dorman 'Rugged Duty' lower ball-joints.

I'll admit, I fell for the marketing hype. But, these might be the only good parts I have ever bought from Dorman.

View attachment 2070View attachment 2071
There's some carnage here too. I broke that bolt for the brake line after I ordered ball-joints and had decided not to just replace the whole upper arms. Not to be defeated by my own crap luck, I drilled and tapped a hole just far enough forward for the metal tab on the brake line to sit flush on the control arm.

Cheater pipe? I'll guess for the ball joints? Been there, done that!!! IIRC I used the jack handle, slipped over my extra long Craftsman breaker bar. Didn't help that the ball joint press set I borrowed from the auto parts had been badly abused and the swiveling tip on the screw was damaged and attempting to seize up, no matter how much I greased it. For the next go-round I just bought the tool for myself; came in handy since I had to do the wife's truck next.

What's that plastic tube setup going? Shop vac ziptied in place to catch chips from dealing with the broken bolt? Not bad.

Richard

 

[someotherguy]

And, like any refresh, a new set of wheels. I had decided I didn't want to cut up the ball-joints this time. The tires are 285/60/18s on what I think are 10 wide Ion's with 5 inches of backspacing. They are wide, but I only rub the inner fenders at absolute full lock.

Picking them up from being mounted/balanced
View attachment 2080

I was also helping my future wife fix up her 93 burb and thought the black 5-spokes would look good on it. It needed new tires bad. If I am remembering correctly, it had the early GMT800 Silverado 16s on it. I didn't think it looked right. I "sold" her my wheels and tires for $25 a wheel, and the old coopers had about one winter left in them.

View attachment 2082

While working on the suspension I realized the brakes were pretty worn, so I ordered up some new pads/rotors/hardware for all four corners. They didn't come in time for the alignment I had scheduled, so I just took the truck to get an alignment with my fresh wheels. The first shop didn't get it right. They actually forgot to fully torque the upper control arm bolts, causing it to come out of alignment rather quickly on our pothole ridden streets. I dropped it off at a shop down the street from where I was working the next morning... and this is where it turned into a real debacle. I appreciate their diligence and willingness to include a free inspection, but I wish they would have asked first. I would have told them to save their time and just do the alignment. They 'discovered' a frozen caliper after disassembling my rear-brakes. One of the pads was almost metal to metal (I knew this) and they wanted to do my brakes. I kindly told them I had brakes on the way for the truck when they called telling me this. I'm not going to lie, I was a little confused as to why they were looking at my rear brakes when I had dropped it off for an alignment. Regardless, they re-assembled it as-was. But the act of freeing that pad allowed for some destruction. This is my brand new wheel after driving about 7 miles home...

View attachment 2076

They were not very apologetic, so I make sure to guide all my friends/family elsewhere. I never got all the metal off. It was cold outside so the hot metal from the brakes rapidly cooled when it hit the wheel. The finish was damaged. In the spots where I did get it off, they were dull and no longer glossy (I actually tried bringing it in the bathtub so it was warmer and i could use hot water). I gave up and ordered a new wheel. I figured it would be better to let them fade as a set. I kept the 'orange' one in case I severely damage a wheel and they stop making them. If you look closely at that corner of the truck, you can still see little tiny orange specks in the clearcoat. I've gotten over it, the 20 year old paint is certainly not perfect.

Here's a pic from when it was all back together. I think it does a good job of showing the offset with the tires just barely sticking out past the fenders. But it also shows the mail truck actually performing its' duties!

View attachment 2083

Sorry for all the individual replies - there's no "multi-quote" like I'm used to on the GMT400 forums.

So the future wife at the time had a '93 Suburban (I'll note with the appropriate '94-up grille upgrade)? Nice! This was her own doing, or with your involvement? My wife drove my old slammed '94 C2500LD ext cab for a good while and really missed it when I let it go. I keep looking for a suitable one to get her back into, but solid older 400's are getting few and far between.

Hate to hear about the bad experience with BOTH alignment shops, but that seems too often how things go these days. The second shop probably meant well and fully expected you'd have them do the brakes, with no way of knowing you had the parts on the way. Unintended consequences and all that. They probably figured you were a nutjob for telling them not to fix them.

Richard