I Have a 68 400 4 sp Convertable, edlebrock Carb, performer intake, fresh restore just got it out after 3 years and does not run good at all, although it did before the restore, the only thing I had really done to the motor was pull the Dist,carb,trany,not much else. Car seems to have crazy vibrations towards the end of every gear (3300-4000 rpm) Where do i start? Ignition? Carb? Vacume? Clutching?