Major vibration, any help..?

[vande97]

I am kind of going threw the same problems as you are i just put the king cobra clutch in and new gears in the rear and i had a bad slip yolk on the drive shaft that had a worn part but any way i got a bad vibration at about 75 anything less smooth as silk. but i took the drive shaft in and they found a dent in it witch under pressure gave a little when i put the pedal to the metal and twisted the drive shafe just a cun# hair but it threw it out of balance. I have the FMS aluminum drive shaft on the way so i think this will fix it hope fully. maby take a look at yours. also have you considerd that you r flywheel could be warped as far as the sound you are getting when you are in netural?
hope this helps a little good luck