Need to upgrade both suspension and drivetrain. What do I do?
 

Well here is my 95 GMC Yukon and I'm doin a single s366 on a 5.3 backed by a 4l80e and hoping to put down 500whp and 500ft-lbs reliably. I have the original floor shift 241 tcase but the 10bolt has to go and I'm pretty sure the the front diff even with the fresh 4.10's would snap like a twig. So what do I do SAS swap, 3link, or 4link weld in kit? I'm limited to the driver side drop since the turbo down tube will be on the passenger side. I need a good ride that doesn't beat my back up, and not higher that 6" over stock or I won't be able to physically get into it and can till tow up to a 5k trailer. I wish I could stay 6 lug so I could keep my current wheels but if I have to I'll go 8lug and just rebuy my wheels in 8 lug. What have you guys done and how does it ride?

Anyone?

Why does the 10bolt have to go?

Just toss a better diff in there and call it good. That's pretty much what everyone else does when they add power, the 10 bolts is still plenty strong. Front diff can take a good amount of power but if you abuse it and do 4WD burnouts/donuts and crap on dry pavement you are just asking for it to explode.

Yea I don't abuse my toys but I do want to do some trail exploring and do a ton of miles without breakage. But basically my lift sucks it's only bolted on and I can't keep an alignment. I thought about welding the upper arm plate onto the frame to make them stronger, and I need to build a double cardan joints to correct the severe rear drive shaft angle on the short wheel base of the 2dr. wobbles at 25-30mph and I can't keep u joints in the rear. Kinda thought 8 lug sas swap on both ends would kinda be a cure all with stronger drive shafts.

How much lift do you have, and what brand? The ifs differential will typically take more abuse than the rear end will, if you are dead set on upgrading your rear end, the 9.5" 6lug from an obs 2500 should be a direct bolt in. The 8.5" rear end will hold up to a lot of abuse, so long as you change out the factory differential carrier, and go with a quality aftermarket posi or locker (i.e. eaton posi, yukon duragrip, or trutrac) of some sort...

What do you mean the truck wont hold an alignment? I ask because a lot of people have different opinions if what it means to hold an alignment...

Rcx 6" but at the 4" level. 6" was way too stiff and the rear skipped around so I dropped the lift leaf out and de-cranked the torsion bars. Rides better but front tires rub when turning so that's gotta be fixed. All the bolts that came with the kit are cheap and the upper a arms bolts keep coming loose amount others so it won't stay in alignment. Just kinda sick of the kit really. And there is no front locker for the ifs.

Arb and eaton make lockers for them.. but there are other things that realy need to be upgraded as well

Lockers for the. 9.25 ring gears but not 8.25 that's in mine.