Just for reference, I have 3.38 gears with a 3 speed OD trans (1968 1st gear synchro Saginaw) in my 1957 Chevy NAPCO truck. It works just fine for me. However, I do have a warmed over 283. I was concerned with the same issues as mentioned in this thread relative to bogging down. But the 283 seems to help mitigate that issue. I got my gears from Patrick's. He gave a discount because I bought two sets (front and rear) and was most helpful.
Note:
I had 3.90 gears, but the front differential had some chipped teeth, so I had to replace them anyway and opted for the 3.38s. I'm working on rebuilding a 348 engine, so if long-term the 283 doesn't cut it, I'll go with the bigger engine (I need something to keep busy).
don
What tires are you running? The gears are only part of the equation.
