2004 RCSB 4x4 - The Mail Truck

[INW-Iron-Steel]

The 4.8 has a shorter stroke than the 5.3/5.7/6.0, or not sure I'm following you on that?

Long crankshaft 6.0 would be perfect to pair with a 4L80e (4L80e swap your truck is what I'm saying here...) Why would want to use a TH350 or weaker 700R4 or first gen 4L60e? They sell custom torque converters to make that long crank work with your LS-based 4L60e.

Other options is to take your 4.8, swap to the factory crank/rods from a 5.3 and effectively convert it to a 5.3. Or crank/rods and bore it to 5.7 for an iron block LS1/LS6...Or do a combination and stroker aftermarket crank. 3.90 or 4.00" stroke. There are a lot of options out there.

Yes, 4.8 has the 3.268 stroke with longer rods. Piston compression height is the same, and the 5.3/5.7/6.0 all shared the same crank and rods.

One of these LS rebuilds is intended for my 93 k1500 Suburban with a first gen 4l60. I have it, that is why I would want to use it. On the other hand, my 04 Sierra has a built 4l60 with 30K on the rebuild. I am not very interested in swapping to a 4l80 at the moment. That would include getting another new transfer case, and my LD 261 is also only 3 years old. The whole objective here would be keeping the cost down using parts I already have and limiting buying new expensive new pieces (transmission). Doing a 6.0 in the Sierra and a 5.3 in the Suburban would require buying two new engines, or an engine and a rotating assembly. I already have two 4.8s, so I would be cutting out the cost of an extra engine and associated crank/pistons/rods. Also, 01+ 6.0s are stupid expensive now. $2000 plus for a 250K mile long block around here. Early 6.0s are going for half that with half the mileage.

I've crunched some numbers, here are my thoughts:

04 Sierra: 6.0 block, 4.8 crank, factory dish 6.0 pistons, 243 heads, and a mild truck cam of some sort. Based on my calculations, should yield 9.2:1 or so compression depending on head gaskets.

93 Burb: 4.8/5.3 block, 6.0 long crank, 4.8 flat top pistons, 317 heads, torque cam or something like the Melling MTC-7. Again, 9.2:1 depending on head gasket. From what I understand, this will bolt directly to the SBC style transmissions using the flat style flex plate from the 6.0?

Neither one of these will be fire breathing race motors. I fully intend to run them on 87 octane, which is why I am intentionally wanting to keep CR under 10:1. Premium is close to $5.00 a gallon here, and I don't have that kind of money to be running 93 in the daily rigs. I appreciate your input!

 

[stutaeng]

Ah, ok...So like a destroked 6.0 then? Should be fine.

I built a 6.0 using a Gen IV block, and sourced a used 5.3 Gen III crankshaft. I took it to my local machine shop along with pistons and everything else for a balancing job. They had to install those heavy slugs to get it to balance since the 5.3 has a lighter rotating assembly weight. I think the balancing was like $300 or somewhere around that IIRC.

 

[INW-Iron-Steel]

Ah, ok...So like a destroked 6.0 then? Should be fine.

Exactly! I think it could be fun in a light weight regular cab.

I built a 6.0 using a Gen IV block, and sourced a used 5.3 Gen III crankshaft. I took it to my local machine shop along with pistons and everything else for a balancing job. They had to install those heavy slugs to get it to balance since the 5.3 has a lighter rotating assembly weight. I think the balancing was like $300 or somewhere around that IIRC.

Good info, thanks! I sort of assumed the rotating assemblies would be exactly the same, but the 6.0 does have larger pistons. Makes sense the balance would be different. I have a machinist friend who might support this type of hooliganism.

The more I read, controlling the 93 4l60 looks like it could be an issue. I may just revert back to buying a wrecked 5.3 powered 4x4 with a cable throttle body.

 

[stutaeng]

Exactly! I think it could be fun in a light weight regular cab.

Good info, thanks! I sort of assumed the rotating assemblies would be exactly the same, but the 6.0 does have larger pistons. Makes sense the balance would be different. I have a machinist friend who might support this type of hooliganism.

The more I read, controlling the 93 4l60 looks like it could be an issue. I may just revert back to buying a wrecked 5.3 powered 4x4 with a cable throttle body.

You don't have to buy an engine that has throttle cable, just swap the throttle body or intake. That's what I did on my V6 to 5.3 swap on my 99. The L59 was from a 2004 Yukon XL with drive by wire. Maybe there's a little difference on the hoses/nipples, but it can still work w/o any issues.

Edit: Here's a thread I created when I swapped the engine. I was very new to this then...https://www.performancetrucks.net/forums/tuning-diagnostics-electronics-wiring-161/04-l59-into-99-4-3-a-558143/page4/

I guess I'd forgotten the oil pressure senders are different 99-02 and 03+ but that's pretty minor.

 

[INW-Iron-Steel]

You don't have to buy an engine that has throttle cable, just swap the throttle body or intake. That's what I did on my V6 to 5.3 swap on my 99. The L59 was from a 2004 Yukon XL with drive by wire. Maybe there's a little difference on the hoses/nipples, but it can still work w/o any issues.

Absolutely. But, if I went the route of buying an entire vehicle I would try to find one that could donate as many parts as possible. With the 93' having a cable throttle pedal, it would be easier to adapt a cable throttle body and associated wiring if I chose to keep the factory stuff. I have heard good things about Aces recently, so I may also go that route when the time comes.

 

[stutaeng]

Absolutely. But, if I went the route of buying an entire vehicle I would try to find one that could donate as many parts as possible. With the 93' having a cable throttle pedal, it would be easier to adapt a cable throttle body and associated wiring if I chose to keep the factory stuff. I have heard good things about Aces recently, so I may also go that route when the time comes.

Agree. Always best to buy the most complete engine you can find. Otherwise sourcing the "little things" winds up costing a lot of time and money.

Since we on the topic of throttle bodies, you can expand your search of engines for the 03-05(?) Express vans. Those kept cable throttle bodys longer, for some strange reason. The 1500 vans ran the 5.3 (with the 4L60e), while the 8 lug 2500/3500 used the 4.8/6.0 (with the 4L80e).

In general, the work vans are the most used/abused/neglected vehicles out there because 99.9% are work vans with miliions of miles. But the passenger vans are normally used by church groups, well serviced and typically very low miles.

Just wanted to throw that out there in case you come across one...

 

[INW-Iron-Steel]

New front brakes! One of the calipers was frozen, which turned out to be a slide pin. I intended to just rebuild the brackets and push the pistons back. One of the piston seals ruptured, so new calipers! That was probably the third brake job on those calipers, and autozone was happy to warranty them. This is what a 10pm gravity bleed looks like after you procrastinate a simply job to the point where all the shops are about to close...

I ended up flushing the lines too, the brake fluid I was initially seeing had a green hue to it. Copper = not good!
Totally budget, I like buying reputable closeout pads from RA. I think these were carquest flavor metallics for $12 with hardware. Dusting is bad, but they stop good.

 

[INW-Iron-Steel]

Since we on the topic of throttle bodies, you can expand your search of engines for the 03-05(?) Express vans. Those kept cable throttle bodys longer, for some strange reason. The 1500 vans ran the 5.3 (with the 4L60e), while the 8 lug 2500/3500 used the 4.8/6.0 (with the 4L80e).

In general, the work vans are the most used/abused/neglected vehicles out there because 99.9% are work vans with miliions of miles. But the passenger vans are normally used by church groups, well serviced and typically very low miles.

Just wanted to throw that out there in case you come across one...

Dumb questions, but how difficult would it be to convert a 2wd 4l60 to 4x4? I've never really thought about it, but I would think the output shaft may be different with a different tail-housing.

A passenger van is a great idea! Also, who thought a 2500 with a 4.8 was a good idea? Have you ever had the terrible experience of driving one of those loaded down? They could have at least used the 5.3!

I wish I could talk my friend into selling me one of his >300K mile 6.0s. He's got to have at least 10 6.0 powered vans.

 

[stutaeng]

Dumb questions, but how difficult would it be to convert a 2wd 4l60 to 4x4? I've never really thought about it, but I would think the output shaft may be different with a different tail-housing.

A passenger van is a great idea! Also, who thought a 2500 with a 4.8 was a good idea? Have you ever had the terrible experience of driving one of those loaded down? They could have at least used the 5.3!

I wish I could talk my friend into selling me one of his >300K mile 6.0s. He's got to have at least 10 6.0 powered vans.

Converting a 2wd to a 4x4 on the 4L60e/4L80e...easy, just have to swap the output shaft...the output shaft is the FIRST thing that goes on the assembly, meaning you have to completely tear down the unit...to get to it.

Regarding the 4.8 on the 2500/3500 Express vans: I suspect GM decided to use the 4.8 on them due to fleet usage, and as they were phasing out the 4.8? IDK, that's just my guess?

They kept the 5.3 on the 1500 vans, and at least some of those were converted using those aftermarket, high dollar conversion companies in the day. I believe they were lower production numbers too (and eventually the 1500 express vans got discontinued), reserving those 5.3 engines for the more profitable pickups and SUVs...

 

[INW-Iron-Steel]

Mt Hebo and the Pacific Ocean. I think my lowered pickup sees more dirt than those lifted rigs on rubber-bands and 22s... Just sayin

 

[INW-Iron-Steel]

New look! I scored these on marketplace. I was told takeoffs from a 24 Sierra, and that checks out because the DOT numbers are same year. I'll take that for under $200.

The 18s with 285s are on the Suburban (and look amazing). The black 17s that were originally on this are goin to my old man. He has been asking me about them for a project he's working on, I decided I'll just give them back.