Not being a expert either i would think 70 degree may lead to some rear end shifting under power. We know the 2 45's hold it at a positive center. My thought would be go to a panhard bar just for the stability for this application. That or you will have to mod the frame to make it work properly.

Where is a engineer when you need one . Hurst there is some great guys here who may have a fix for you. Hang in here and lets see the outcome .