Hello all,
I am starting a new build on a 2008 GMC Sierra 1500 4x4 VortecMax The goal is a truck that looks pretty unassuming from the outside but be highly capable both on road and off. It already has a 6.0, 4l70, the hybrid 14 bolt rear end with limited slip, and 4.10 gears. I don't have the entire build figured out yet, but I do have some big things already in the works that meet with the build intent. Here is the things on order or in hand so far.

1. Boost District LSA supercharger kit with 850 FIC injectors and the upgraded intercooler kit.
2. Sloppy Stage 2 camshaft
3. GM performance roller lifters
4.Deatschwerx 400 complete fuel system
5. texas speed dod and vvt delete kits
6. Texas speed headers, 17/8 primaries
7. CHE trunnion kit
8. MSS crank pinning kit
9. EBC green stuff pads
10. Dual valve spring kit from Summit
11. Dual exhaust cutouts (plan is to tie this into the factory system so its quiet as a daily, with cutouts for max performance)
12. Innovate PSB-1 which reads boost and AFR and can open the bypass valve on the supercharger if anything goes wrong.

Planned future upgrades
315/70/R17 tires, either K02's or Continental terrain contact.
Upgraded suspension, not sure on the plan here, still doing the research. I want to fit the larger tires without jacking it up in the air. The absolute minimum amount of lift possible. Might have to either massively trim the fenders or go with fiberwerx fenders. I also want to upgrade the transmission and 4x4 to be usable on dry pavement. it has the automatic 4x4, which i want to make work like AWD while still being able to lock the center diff and get true 4x4. I have no idea if that is possible, or if it already works that like. Still have to do some research there as well.

I am also open to suggestions from people that want to have input. Have I forgotten something critical? Is there something you can think of that would fit this build philosophy that I haven't listed? Let me know.

 

the easiest way I can suggest doing your AWD/ locking center diff/4lo is using the H2 transfer case, TCCM and maybe BCM. ones from 08/09 trucks might speak the same language as what your truck is already looking for

 

That's a good idea, i will look into those.

 

Was doing a little research, and it looks like the h2 t-case has full time awd, then a 4 hi and a 4 lo setting. Is that how they work?

 

That is correct, and that sounds like what you wanted. The T case in the H2 is AWD with a locking center diff and the ability to have 4lo, which is somewhat uncommon among American AWD vehicles that can lock the center diff

 

Thats pretty much exactly what I was looking for. Does anybody know how well they hold up to power?

 

Probably just as well as any other t case. You'd be the first to try this, and very few ppl have built performance oriented H2s, so not a lot of data out there

 

Judging by the 2500 axles under them I'd think they would put a stout T case.

 

08/09 cases are 32 spline input, 03-07 cases are 27

I am not an expert on that case, so I cannot comment on input shaft swapability

I prefer the ole 2wd/4wd modes of T case, takes a lot of power to do AWD burn-outs ahaha

 

Well the lkq up the road from me has an 07 h2 in the yard. Gonna go check on it sunday.