We have one member who adapted GT quad shocks to fit his v6, said it helped a lot, you can also get torque arms, but they are a bit expensive, cost you about 3-4 hundred bucks I think. aftermarket upper and lower control arms of various types help. I just did a swap on my GT with an 03 Cobra for his IRS rear end and suspension, love it.
rick, you don't have to do anything to adapt quadshocks to our cars if you have upgraded to an 8.8. at least the 99+ cars are predrilled to accept the bracket bolts. when i dropped in the 8.8 rear i just bolted it all up. it's a sorry substitute though and it is worth it if someone welded brackets to the axle housing on the rear.
(quad shocks are crappy stock alternatives to getting lower control arms)
Yeah, I think it was horse that adapted some to fit on his 7.5 rear end??? Not sure. I had a set of Granatelli upper and lower aftermarket control arms, but they went on the Cobra with the IRS swap. They were not the best on the market, just mediocre ones anyhow.