I have a 1987 Ford mustang GT Foxbody 302 block made into a 347 stroker and a T5 transmission. I hade to change the rear main seal due to a leak and ever sense I replaced the rear main I have had a very violent shake in my shifter handle at higher RPMs I have had tires balanced drive shaft balanced new crossmember mounts new tranny Mount new motor mounts new throw out bearing but still it vibrates at high RPMs anybody know why thank you for your time and help