One issue the "GM" A body needs addressed vs the B body, is the rear suspension. As bite increases, IE stickier tires, the coil sprung 4link will show it weaknesses fairly early, with twist/hop. A lot of people just went to the bolt on ladders, and while they did a reasonable job, I used "no-hop" bars on several cars with decent results. A right side air bag for a little preload on big torque/hp cars can make a big difference also.
