1967coronet440
Well-Known Member
My 505 uses the 4.25”My 512 has a 4.25 stroke crank, and doesn't smoke or burn oil. And it goes to 6500 RPM or more quite often. Milodon hi volume external feed pump, with a windage tray. A longer stroke crank may need a special tray made for that, mine does. Find out your exact stroke. Is it 4.15? I think that's what a 505 has. 400 block? You could also try a higher viscosity, 20W50 oil. What are you running now?