Tell me about stock 250 cams/timing chains..

[Duane]

Ok, I'm being cheap...again. I'm rebuilding a 250, around 1978, and don't want to replace the cam with an aftermarket one at this time. Are all the 250 cams the same? And is it recommended to use a pre-72 timing set? I need a little extra kick from it. Too bad the head was cracked, I have to dig out one of my older heads now. I'm being cheap on the Maverick, since I am building two engines at once. I just bought some of those aluminum SCJ heads for the Mustang, and it gets most of the money. Any help appreciated...

 

[MustangSix]

I don't think there's much if any difference in 250 cams from year to year, but the timing set did change in 1972 to retard the cam timing. That reduced cylinder pressure and NOX emissions. The earlier set restores some of the torque and hp.

This is a common mod on 460's also, BTW.