I have a 1987 Ford Mustang Fox body GT with a 347 stroker and a t5 transmission , I needed to change my rear main seal so I changed it put it all back together the same way it came out and now I have a bad vibration in my shifter at higher RPMs it happens in any gear and it also happens if I'm sitting still and rev my car up to a higher RPM, I get the vibration in the shifter and it is pretty violent, since I got the vibration I have changed crossmember mounts motor mounts tranny mount new drive shaft that's been balanced with new u joints tires are balanced and I have also checked the harmonic balancer and it is fine so please help thank you guys
