Looking at a project car, 280ZX coupe or Z31 coupe. Probably VQ turbo, Skyline trans/susp cradle, road/circuit car. From the little around the Z31 body is not as stiff as the 280ZX coupe, and of course heavier.

Any Z31 racers around here, educated opinions, whatever? Weight and body rigidity are it, suspension, brakes and power train can be changed, no problem.

 

Find a hardtop car. The Z31 did quite well as a factory racer back when it was new. Up to you how creative you want to get.