YJ 8.8 driveline vibration need advice
Ok forum I am about to surrender I have a 89 YJ I6 with ax-15 and 231 with SYE, I just did an 8.8 swap I have been chasing a vibration that occurs occurs around 60 mph and up. Here's the full run down. I have a DC an XJ cut down once for the dana 35 and cut down again for the 8.8. Each time I have been told it is balanced, I had a vibration with the dana 35 installed at 68 mph with the 8.8 it's around 60mph. The other day I took rear driveshaft off an drive it with only front on wow no vibration, installed rear DS and vibration came back. I checked TC yoke this morning with and it was tight no play, I then started vehicle put it in gear and ran it yoke looked great. I also checked angles and if I did it right I have 5 degrees at yoke and 15 degrees at axle pinion. I'm simply at a loss and before I go and buy a new rear drive shaft I want to make sure I am not just wasting money trying guess what it could be. I did notice torque arm bushing was a not tight on torque arm but the transmission mount looked to be good.
I need so serious direction, do I take the driveshaft to a third place to have it checked???