1stDeuce,
Wow, thats pretty much the kinda feedback I was looking for, thank you very much.
I am aware of the front diff oil pan mounting, weird as all hell. I am also thinking about one with a 5.3 motor just because thats what I am very familiar with and can tune it to be exactly how I like it. Not sure about the front diff configuration in the V8 vs I-6. If you know anything about that let me know.
Interesting you mention how tail happy it gets even with the 3.73 gears.
Tell me more about the 3" body lift, you mentioned that it's pretty hard on stuff, what stuff is it hard on?
I know that I want to play with a GMT360/370 platform, but not really sure which direction I want to go with it. I either want to do bad and stupid things with it and build it as a dedicated 4x4 trail rig (with GM IFS, I know, feel free to give me crap about this one) or a really screwed up "practical" backroad 2wd street legal truck. In either case I want at least 35" tires on it.
I think that I am narrowing my search down to a TB with 5.3, I might have to pay a premium for it but with all the parts I have laying around it will be a huge savings over the entire build.
The 5.3l also has the diff mounted to the oil pan.
The gear ratio has nothing to do with the tail happy bit... On slick roads, it is notable that the transfer case waits to engage the front axle until the rear axle slips, and it's kinda "sloppy" compared to the auto transfer case in pickups. If you happen to be turning a corner, or at an intersection, and the rear tires slip some as you tip into the throttle the rear starts to slide out before the front starts pulling. (A spinning tire has no lateral grip.) It can be kinda fun once you know it happens, and stability control will help catch it when it happens if you are an un-suspecting driver. As this is an early platform for stability control, the system is tuned to be "safe" vs. fun... It unfortunately tends to be a bit heavy handed with throttle reductions if the going gets loose. Again, this is 2006+ only. Earlier trucks had no traction control, except perhaps some 2wd trucks with engine only TC. (Not recommended...)
I don't think a 3" body lift is especially hard on anything. I was perhaps unclear when I said 2" max, but I was talking about lifting the front suspension more than about 2" as being hard on things like CV joints, tie rod ends, and ball joints. 3" is, IMO, asking for trouble, and the only way to do this is to greatly reduce droop travel from static ride height. This will make the truck ride pretty harsh, and results in limited suspension travel in a practical sense, as your "normal" ride height is so close to full droop.
The 3" body lift will look pretty bad, IMO, as the frame is already hanging down below the body quite notably. at 3", you would be looking at the full frame below the body. A 1" or even 2" body lift might be an option for a little more clearance.
Honestly, if you think you HAVE to have 35's, I would recommend that you're looking at the wrong platform. Those are, IMO, HUGE tires for a small SUV, and you're going to end up with a POS that drives like crap, and doesn't work well offroad anyway. Gearing is going to be pretty terrible, as it's unlikely you'll find a 4:10 V8. If a wheelin only rig is what you want, then forget lift and just whack the fenders till those tires fit, but that's not really expo style, it's Pirate4x4 stuff... I'd have to take another look, but I don't think 35's will package even if you remove the front fenders... Seems like other body parts are well in the way, like rockers, floor, radiator support, and perhaps even the frame... Going to a wider offset wheel gets tires away from the frame, but then they swing an even bigger arc into the floor, radiator support, etc. The 6 on 5" bolt pattern for TB is pretty specific to that platform, limiting aftermarket wheel selection, but the 17" wheel is pretty wide, so you could run a decent size tire on it.
There is a thread here where a guy has a 370, and he's got about 3" of lift at the front. I think he's running a 32 or 33" tire. Perhaps he would have more wisdom for you...
https://expeditionportal.com/forum/threads/my-04-trailblazer.216113/
Hmm. Here's what you're thinking of I bet... Older thread, but good info and ideas, and he's got 35's on a TB:
https://blazerforum.com/forum/lifting-tech-44/2006-trailblazer-35s-57926/
If you do this, you better start a build thread!!