I never have driven a car with sfc.s and tubular everything with poly bushings everywhere. i also have a relocated torque arm mount. Should i be feeling a vibration and or hearing a whine while under cruise condition. the noise goes away fast while accelerating, if its just rolling along, not on the gas not slowing down really, it vibrates more than im used to. Did i mention the car also has 4.10s and an aluminum d/s? help me out guys. no the d/s isnt out of balance or phase either.

 

I have the same problem.
DD subframes, granatelli Gload brace and poly bushings everywhere.
My mirrors vibrate at the top of each gear, I have to shove some wadded up papers into the crevice on the console it vibrates so bad.
I too have an aluminum driveshaft and as far as I can tell nothing is misaligned or loose.
Some people actually remove the poly tranny mount because they can,t take the nasty vibes it can produce.
I take it as part of the game.