the car only vibrates hard from 70-80 at WOT or when accelerating very quickly (rattles the change in my console pretty bad)...
If i am chugging along between 70-80 the car is fine...(no vibration felt)
The wierd thing is that i went from 3:73's to 3:42's and the vibration stayed consistant at 70-80...

would low gear oil do this? because my rear is leaking pretty bad... (from the front and rear)...

i have replaced: rear rotors, driveshaft, set the pinion angle, transmission, damper pulley, rearends, u-joints, spindles, front rotors, hubs, mounts, had the wheels balanced... i pretty much did everything and i still have this GD vibration...

i'm running out of ideas... and i'm wondering if bad springs could cause this? i am frustrated and clueless...

can someone either help me or refer me to a drivetrain specialist... (in the SW PA area)

thank you