i think the rear is 3:30 its from a 55 belair-I checked it and thats what I came up with. The tranny was rebuilt for a V8 -i know this because my friend had it rebuilt and the input splines are i think 24 which matched up to a nova 10.5 clutch disk and pressure plate. I was also thinking about timing maybe or I had also heard that alot guys go to dual or four barrel carbs because of this problem.