Im pretty sure my issue is a result in a miscalculated pinion angle, and the stock driveshaft that has the rubber on the pinion end. Engine is a built 350 using stock motor mounts with a bolt through them and sealed up with 3m window weld. trans mount is a poly and actually gives more than a stock rubber from the parts store. is it the bushings that caused the issue or is it a drive line issue. don't want this to happen with the th400 I have now.
No. What you currently have in your driveline would not break your bellhousing. Pinion angle would not do that. If the angle was too severe,it would just cause wear on your u-joints. If you had rubber engine mounts AND a solid steel transmission mount,then you would break the tail housing of the transmission. But you do not. You have a urethane mount,which still have flex to it. The engine and transmission are bolted together as one,and can still move as they should. How much power is that engine making?
When it was mounted to engine there may have been some thing between the block and trany . and was broke before you drove it.
I can't see mounts being the issue. A mate & I cracked one on a TH-180 years ago. Didn't have the trans lined up correctly & decided to let the bolts pull it into place. Not a happy ending.
