I'm running a stock (.030 over) 250 with a 4-speed from a '74 Nova in my '65. With the 3.73 rear end, it pulls up great empty, and can handle my flatbed trailer at normal speeds. I sometimes wish for an overdrive gear, but I think the 250 was designed to operate at a few more rpms than the older 6's.
And, I get about 20 mpg, if I keep my foot out of it!

cm


If you can't fix it with a hammer and screwdriver, you need a bigger hammer.
1965 Chevy C10