Axles/ suspension

[JoshM572]

Hello, im new to the forum. Im looking for ideas/advice on my 2000 gmc sierra z71. I have had this truck for quite some time but about 5-6 years ago i blew the engine and it has sat in my yard since. Im wanting to get it back up and running again but my intentions and goal is to turn it into our off roading/camping rig. My plan is to SAS it on the front. Id like to run 37-38 inch tires which i know is quite alot of stress on the drive components. Im curious if it would be wiser/ smarter to grab a rear axle from a hd truck of the same generation and use a dana 60 for the front axle or should I stick with the factory rear axle? I plan on re-gearing the truck either way i go but just curious what options i have if anyone has done anything similar? Thanks for any advice!

 

[ORVietVet]

Welcome to the forum from Oregon.

I used to own a purpose built 73 Blazer that had a nickname of BRUTUS. I had 38" tires with a GM 14 bolt at the rear and a Dana 60 at the front. IMO, get an old square body that already has a full front axle and then "spiff" it up. If you plan to do this work to your 2000 Sierra, get the pocketbook out. Cut all your hair off because you will end up tearing it out if you proceed with your attempt.

If you are interested in knowing how I set Brutus up, I am glad to help. I had been to Moab and all over the Tillamook mountains, here in Oregon. Rock climbed all ove

 

[JoshM572]

Welcome to the forum from Oregon.

I used to own a purpose built 73 Blazer that had a nickname of BRUTUS. I had 38" tires with a GM 14 bolt at the rear and a Dana 60 at the front. IMO, get an old square body that already has a full front axle and then "spiff" it up. If you plan to do this work to your 2000 Sierra, get the pocketbook out. Cut all your hair off because you will end up tearing it out if you proceed with your attempt.

If you are interested in knowing how I set Brutus up, I am glad to help. I had been to Moab and all over the Tillamook mountains, here in Oregon. Rock climbed all ove

Well i appreciate that idea, but considering i already own this truck and have to put a new engine and everything in it already and its pretty much torn apart right now anyways I still would like to try and pull it off. Even though i understand the fact this is a huge undertaking but ive already set aside money for this project and plan to purchase the solid axle swap kit in the next month. It currently already has 35’s on it with just a rough country lift on it so worst case is i do the solid axle swap on it and keep it at 35’s. The kit im getting for the SAS has the option for a dana 44 or a dana 60 front axle but my dilemma is what to do in the rear.

 

[4silverado]

Here is one company that I know of that does SAS conversion kits.

I have bought a few things from them back when I had my 87 Chevy. They make quality stuff and I would buy from them again.

I will agree with ORVietVet, conversions like this are never cheap unless you can do all of the fabrication or installation yourself.

 

[ORVietVet]

OK. 35's are good for just regular trails and camping. Rougher areas require clearance and therefore bigger tires. Dana 44, front and rear would be the way to go IMO.

 

[JoshM572]

Here is one company that I know of that does SAS conversion kits.

I have bought a few things from them back when I had my 87 Chevy. They make quality stuff and I would buy from them again.

I will agree with ORVietVet, conversions like this are never cheap unless you can do all of the fabrication or installation

Here is one company that I know of that does SAS conversion kits.

I have bought a few things from them back when I had my 87 Chevy. They make quality stuff and I would buy from them again.

I will agree with ORVietVet, conversions like this are never cheap unless you can do all of the fabrication or installation yourself.

View attachment 4664

I do plan on doing about 90% of it myself and i have friends that can help with any fabrication things i need done. So im doing it about as budget friendly as i a person can for what im trying to accomplish. Ive seen one guy via social media with the half ton silverado doing the dana 60 swap with 40’s on it. But i dont know everything that went into getting it to that point either. Im also aware of the issues doing a build like this can have on a drive train so im just trying to do as much research as i can before i pull the trigger on everything. I know guys run and wheel 38’s on factory jeep axles but they may be more robust than I am aware of.

 

[JoshM572]

OK. 35's are good for just regular trails and camping. Rougher areas require clearance and therefore bigger tires. Dana 44, front and rear would be the way to go IMO.

OK. 35's are good for just regular trails and camping. Rougher areas require clearance and therefore bigger tires. Dana 44, front and rear would be the way to go IMO.

Do you think the dana 44’s with a re gear can handle the 37-38 inch tires?

 

[ORVietVet]

Do you think the dana 44’s with a re gear can handle the 37-38 inch tires?

That depends on the trails or obstacles you plan on traveling on. I used 38's for hard tight trails and rock crawling. I also used the GM 14 bolt and Dana 60 because of the extra weight, gearing and the clearance that was built in to my Blazer and when all that happens, there is way more stress on the steering and suspension. If you are just driving on pavement and mild trails to go camping, then Dana44's can handle that but if you decide to go "rougher" then have plenty of spare parts. My rig was called "BRUTUS" for a reason. I did not break, except for some steering arm bolts one time. I had 4:88 gears with Detroit Lockers, front and rear.

I was at MOAB and was at Potato Salad Hill and I had made it to the top after a local said I was the 3rd Full Size to ever get to the top but he pointed to a different line that no full size had ever made it to the top on. I tried it. I did not make it and rolled 3 full times to the bottom and ended up on my tires. 2 tires were blown at the beads. I jacked up and aired up with my on board air compressor and drove out of there. With Dana44's, I would have broken some things. I had some bent stuff but still drivable.

The bigger the tires, the more clearance you need. The more clearance you need, the stronger the rest of it needs to be, with the additional stress that comes along with that.

 

[JoshM572]

That depends on the trails or obstacles you plan on traveling on. I used 38's for hard tight trails and rock crawling. I also used the GM 14 bolt and Dana 60 because of the extra weight, gearing and the clearance that was built in to my Blazer and when all that happens, there is way more stress on the steering and suspension. If you are just driving on pavement and mild trails to go camping, then Dana44's can handle that but if you decide to go "rougher" then have plenty of spare parts. My rig was called "BRUTUS" for a reason. I did not break, except for some steering arm bolts one time. I had 4:88 gears with Detroit Lockers, front and rear.

I was at MOAB and was at Potato Salad Hill and I had made it to the top after a local said I was the 3rd Full Size to ever get to the top but he pointed to a different line that no full size had ever made it to the top on. I tried it. I did not make it and rolled 3 full times to the bottom and ended up on my tires. 2 tires were blown at the beads. I jacked up and aired up with my on board air compressor and drove out of there. With Dana44's, I would have broken some things. I had some bent stuff but still drivable.

The bigger the tires, the more clearance you need. The more clearance you need, the stronger the rest of it needs to be, with the additional stress that comes along with that.

I do not intend to do any hardcore rock crawling with this rig. I plan to do medium to the occasional hard tight trails. I live in Arkansas and we have the ozarks which are notorious for having deep deep mudd and deep deep water crossings. So those are the main reasons i want to run the 38 inch tires we will have the added weight of gear as well so that is something i am definitely considering.

 

[Tonimus]

Welcome to the group. I'm in AZ, so truck parts are pretty prolific here.

If I HAD to have a SAS GMT800, I would use modern-ish F250 or F350 front and rear axles. You're going to have to do a LOT of fabrication for 37/38" tires. Lots of lift, maybe 8".

All things being equal, 35" tires only give you 1.5" less ground clearance than 38" tires. But that makes a big difference in forces translated to the running gear.

 

[Cadillacmak]

Welcome to the forum from Alaska.
My opinion is what @Tonimus just said, along with a 4L80e swap. If you go with the chevy axles (dana 60 front 14bolt full floater rear), get a square body NP208 to bolt on the 4L80e.

 

[JoshM572]

That depends on the trails or obstacles you plan on traveling on. I used 38's for hard tight trails and rock crawling. I also used the GM 14 bolt and Dana 60 because of the extra weight, gearing and the clearance that was built in to my Blazer and when all that happens, there is way more stress on the steering and suspension. If you are just driving on pavement and mild trails to go camping, then Dana44's can handle that but if you decide to go "rougher" then have plenty of spare parts. My rig was called "BRUTUS" for a reason. I did not break, except for some steering arm bolts one time. I had 4:88 gears with Detroit Lockers, front and rear.

I was at MOAB and was at Potato Salad Hill and I had made it to the top after a local said I was the 3rd Full Size to ever get to the top but he pointed to a different line that no full size had ever made it to the top on. I tried it. I did not make it and rolled 3 full times to the bottom and ended up on my tires. 2 tires were blown at the beads. I jacked up and aired up with my on board air compressor and drove out of there. With Dana44's, I would have broken some things. I had some bent stuff but still drivable.

The bigger the tires, the more clearance you need. The more clearance you need, the stronger the rest of it needs to be, with the additional stress that comes along with that.

Welcome to the group. I'm in AZ, so truck parts are pretty prolific here.

If I HAD to have a SAS GMT800, I would use modern-ish F250 or F350 front and rear axles. You're going to have to do a LOT of fabrication for 37/38" tires. Lots of lift, maybe 8".

All things being equal, 35" tires only give you 1.5" less ground clearance than 38" tires. But that makes a big difference in forces translated to the running gear.

Thats a fair point ive gotten this idea from this truck(see posted pic). He is running dana 60’s with 40 inch tires. There is a swap kit that i found that is very diy friendly and uses either a dana 44 or dana 60 from a dodge. It allows you to keep your factory abs break system as well as keep your push button 4wd so thats probably the kit i will likely go with. It is the same kit this guy used as well. But i also do not intend to run 40 inch tires like this guy did

 

[Cadillacmak]

Thats a fair point ive gotten this idea from this truck(see posted pic). He is running dana 60’s with 40 inch tires. There is a swap kit that i found that is very diy friendly and uses either a dana 44 or dana 60 from a dodge. It allows you to keep your factory abs break system as well as keep your push button 4wd so thats probably the kit i will likely go with. It is the same kit this guy used as well. But i also do not intend to run 40 inch tires like this guy did

What transfer case do you have in it? I would think with those axles and tires and any real work load, you will be swapping transmissions and T-cases often.

 

[JoshM572]

Welcome to the forum from Alaska.
My opinion is what @Tonimus just said, along with a 4L80e swap. If you go with the chevy axles (dana 60 front 14bolt full floater rear), get a square body NP208 to bolt on

What transfer case do you have in it? I would think with those axles and tires and any real work load, you will be swapping transmissions and T-cases often.

Right now all the drive train components are factory. I had put a 6 inch rough country lift on it with 35’s before the engine blew up. But also i do not intend to turn this truck into a full blown rock crawling monster. I want to be able to do moderate to slightly difficult trails and be able to handle deep water and mudd. It will be for lack of a better word a “overlanding” truck. It will have gear weight as well. My vision with 38’s came from that pic i posted along with the fact that jeep guys run those sizes with seemingly no issues but maybe those axles are stronger than i am aware of.

 

[Tonimus]

Jeep guys break stuff all the time, they just carry lots of spares. Additionally their steering and suspension geometry means critical parts are stressed differently than they are on GMT800s.

I would leave the 6" lift and 35s on it until I broke something or needed more clearance. I had a '78 heavy half ton RCSB. Got that into LOTS of places with 35s. Loved to go mudding in it with a NP203...

 

[JoshM572]

Jeep guys break stuff all the time, they just carry lots of spares. Additionally their steering and suspension geometry means critical parts are stressed differently than they are on GMT800s.

I would leave the 6" lift and 35s on it until I broke something or needed more clearance. I had a '78 heavy half ton RCSB. Got that into LOTS of places with 35s. Loved to go mudding in it with a NP203...

Well i know im definitely going to do the SAS for the front but beyond that maybe leaving it with 35’s is the way to go. I want the solid axle because these trucks either have very weak front axles and differentials or i have bad luck with them because I had already broken 2 axles on it by going through a very very small mud hole and another one climbing a steep dirt road not even off roading.

 

[99Sierra2500]

Welcome from Indiana. Looks like a fun truck. I know a lot of people break the factory setup, and like yukon as a replacement. I had 65 wagoneer I broke a dana 60, ripped the perch off and broke the tube. 4x4ing in my current rig I have trashed tie rods, transfer case, and u joints. I think one things about these rigs, is like the jeep they are heavy. CJ is about half the weight, and a squarebody a ton less too. Whatever you go with, keep us posted, I would like to hear how it goes.

 

[ORVietVet]

Another thing. You want less chance of breakage? Some how, some way, use an NP205 gear to gear transfer case.

 

[JoshM572]

Welcome from Indiana. Looks like a fun truck. I know a lot of people break the factory setup, and like yukon as a replacement. I had 65 wagoneer I broke a dana 60, ripped the perch off and broke the tube. 4x4ing in my current rig I have trashed tie rods, transfer case, and u joints. I think one things about these rigs, is like the jeep they are heavy. CJ is about half the weight, and a squarebody a ton less too. Whatever you go with, keep us posted, I would like to hear how it goes.

I was looking at the yukon gears for re gearing the truck and adding lockers as well. They seem like good quality options

 

[Cadillacmak]

Another thing. You want less chance of breakage? Some how, some way, use an NP205 gear to gear transfer case.

Well shoot, if we are going to a NP205, get a divorced 205, do a 4 link rear suspension with a 14bolt full floater and a 3 link front with panhard bar with a dana 60. You would have some serious travel and articulation. Use jeep springs from Metalcloke!

I need to run for congress, spending your money is fun!