So I installed the FC transmission with a good transmission mount and it shifts great (thanks to Redline) but there was still a vibration issue. So I decided to re-lash the rear end but when I removed the driveshaft again I saw this...
So time for a new driveshaft. The rear end does have a little play in it also so I will be adjusting that as well. (Until I find 4.78 gears sometime soon I hope.)