M,
Maybe you can check in to the 392 stroker. Lots of people have been happy with it for a long time now, with no issues or premature side-load wear, etc. Seems like a sweet motor. Tom at FE Specialties in Sac or Ben at Smedding in R.C. could build you this, and having your motor builder locally does have its advantages. A number of people around here have experienced why they should have done this first hand instead of mail-order motors a number of times; then bringing their motors to the local guys here to get it fixed anyhow.
Good Luck.