Bought a 91 foxbody with a 347 stroker, twisted wedge heads and a bunch of other goodies etc. Most of the engine, Trans etc on has 500 miles on it. Problem I'm having is a nice vibration at idle you can feel through the shifter and gets worse when you idea and rev it etc. I'm guessing there's a balance issue. The block he said is internally balanced but that would mean the balancer and flywheel need to be neutral correct? Want some info before I go taking out the Trans etc.