I`m getting to this thread a little late but we`ve put a lot of time into developing suspension for these cars so I figured I`d share a little. Most mods for these cars (G bodys in general) are aimed are stiffening the suspension. That`s mainly because the suspension geometry is pretty poor for a performance handling standpoint. The RC is too low in the front and too high in the rear. The camber curves are backwards (+ in jounce) and so on. The B spindle swap attempts to rectify these 2 by being taller than the stock spindles. This is a good thing! However the steering arms are longer (which slows the steering and makes the already so so ackerman angle worse) and more importantly they`re 5/8" lower than the stock steering arms...which are already 5/8" too low! Bumpsteer city here we come. The result is that you still need stiff springs and big bars to keep travel to a minimum. That`s a bad thing. The tall truck UBJ is a great,easy partial fix. I`ve done that one myself with good results. The problem is that the taper is different than the G spindles and you end up with very little load bearing surface on the UBJ stud. Not good. Reaming the spindle fixes that...but...it allows the stud to drop in far enough that you hardly gain any geometry improvement.
We found a great way around that with Howe`s new PC series modular ball joints. We`ve been going wild with these things.
Stronger than stock,greasable, adjustable for wear,and rebuildable we assemble them with specific taller than stock studs to change the geometry exactly how we want. Wait,it gets better! Using the tall lower ball joints improves the suspension geometry even more (raises the RC to between 2"-3" *above* the ground and reverses the camber curves so you get significant - gain in jounce) plus it gets rid of 80% of the stock bumpsteer! We finish it off with PPR adj. UCAs in either standard or our own ProLite series. After trying countless alignment setups we`ve settled on -1/2 camber,+4.5 caster and 0 toe for performance street use. With the geometry tweaked the car doesn`t require as much spring rate or front sway bar. My daily driver is running this setup (our StreetComp Stage2 package) with factory F41 springs,stock F-41 frontbar,our chassis bracing package and a 1" rear bar. It rides nice and soft but has great turn in and the overall handling is so much better than stock. Where the tires used to tuck under and squeal away it just grips and goes. What`s more it`s much easier to drive fast. This particular car is a driver,not a hot rod but even without big horsepower I haven`t found a hat backwards,gopher hole muffler import-mobile that could loose it in the twisties.
They keep looking in the mirror,like "What is that big old car still doing back there?!?!"
Of course if you wanna up the ante to run with the big boys,slightly stiffer springs (Moog 5658/5413 in a GN),a set of QA1 adj. shocks (set at 5/4),Del-a-lum LCA bushings,1LE rear LCA bushings,Edelbrock or Currie rear UCAs and some sticky 17"s will let you run with 3rd/4th Gen F bodys etc. More than that? Last stop. G-5. C-5 Corvette forged aluminum spindles,13"/PBR brakes,7075 T-6 CNC steering arms. Optimized suspension geometry,2" drop,improved ackerman, quicker steering,less weight. Our test car running this package with an LS1 and 6 speed and most of the goodies listed above and our prototype adj. road race 3 link/PHB rear suspension will hang with anything on the road. Compared to our `99 C-5 with some upgrades it`s darn near equal,both will scare you (or at least me!) stupid before you reach the car`s limits.
Sorry about being so long winded but you asked....
Mark
