Drivetrain Vibration

I'm sorry it took me so long to reply.
Actually there are some updates.

I just balanced my crankshaft.
My 318 runns smooth a f (it even has a rattler balancer).
It has been balanced with flexplate and balancer mounted.

I have redone my 8 3/4 (new bearings etc.)

I changed my tranny mount (prothane).
Before my tranny was offset.
Now it lines up great ;)

I have also redone my 904 because the new tci converter exploded.
So i installed the good old hughes converter.

AND STILL...
now at 70mph (before 60mph) the car starts to vibrate and the faster you go the more it shakes the hell out of you.. :/

Slightly vibration are noticeable at lower speed but nothing that bothers me.

You were right. I had two problems.
But now there are vibrations at higher speed only..