Baystate Jeepers

I never really solved this issue and thought I should finally resolve the issue.

If you had a un-ballanced front drive shaft could that result into a pulsating vibration similar to quickly driving over the warning strip on the side of the road only between certain speeds?

Yes, I know one of the ways to test is to remove the front ds. Just trying to figure out if this could be a drive line vib cause by the front ds.

Try deeper pockets. Should fix everything.

need to borrow your pants, my pockets aren't deep

I can't drive 55.

...and yes, a fubar'd front shaft spinning can cause a vibe at certain speeds. Generally, if you can wiggle the spline area and it has a decent amount of play, that could be the cause.