hey everyone,
I have a 75’ 280z that I swapped an LS/T56 into, R200 short out of a Q45 and custom CV axles from T3.
i’m having some bad balance/vibration issues.

I’ve had the tires replaced, the wheels balanced, the driveline rebuilt and balanced, new U joints, and I’ve currently got the car on the lift and am running it to see what is shaking.
the wheels seem to be the worst part, they have like 1/16-1/8” of runout.
but I took the rear wheels off and the car still seems to be vibrating pretty bad in part throttle conditions. The engine is vibrating almost like a misfire. Maybe, idk, not an expert, computer isn’t throwing misfire codes.

i have poly bushings on the trans mount and in all the rear suspension components, and I’ve heard they are harsher than rubber, but it seems PRETTY vibrate-y to just chalk it up to stiff bushings?

hail-Mary here, anybody live in the Bay Area that I could swap some 4-lug wheels from and drive my Z to see how it feels with different rims and tires?

thanks

josh