Tom,
What's your theory re deep groove ball at the rear and SA roller at the front? I was thinking a self aligning roller at the rear would be capable of coping with a higher radial load than the deep groove ball. Bearing loading at the flywheel end is surely higher than the front? If there is no room for expansion it might cause problems,such as overloading the thrust faces of the rolling elements and inner races spinning on the crankshaft. You have probably thought about these possibilities and I am talking through my er... hat. Tony Press who is a contributor on here will have a better idea than me I think.
Good luck,
Dave.

Location: Sheffield