I'm running a 57 vintage 235 with a 85 Camaro T5 so the gearing isn't my primary issue. Well lets put it this way, not an issue as long as it isn't too low (numerically). I think with this combination a 3.90 would be OK. I was also thinking of the early Japanese mini trucks as a possible donor. They were plenty strong enough and although I haven't had the chance to measure one I think about the right width. I know I'll have to weld some spring perches on no matter what I find to fit. My luck would never allow otherwise! With all the crushing that went on around here in the last couple of years they might be hard to find.