[Mikey]

Matt,
Sloppy "roll" feeling in cornering is not usually noticed with 5 lb difference in tire pressure. That feeling is usually related to suspension related components and for sure the bushings you mentioned could be a culprit.

tire pressure variances mostly affects grip, so if you find the car not turning in, oversteer, understeer or lack of grip under accelerations then tire pressures is one of the easiest things to adjust first.

modern tires may require different settings than what the door jambs indicated in the 1990's, but it is difficult to say which is best. My C6 Z06 door jambs call for 30psi cold and I have gone to that setting on my '91 ZR-1 with happy results. Better grip on acceleration and good room for growth as the tires heat up (usually end up 6-8psi higher if at the track for example).

35psi is really borderline for cold psi. I think you are giving up considerable grip running the tires this high. Of course the tires will last longer, and maybe a slight increase in fuel mileage, but these are not usually the goals of a ZR-1 owner..

Try 30-32psi front and 28-30psi rear is my recommendation.

Cheers,
Mike