David Lee said, "Can't remember who it was either but I remember he ran in a Pinto. I thought it was a MP car."
I think Mr. Chapman nailed it; it was Bruce Sizemore's Pinto, running in what I seem to remember was "I/Gas Coupe."
Modified Production had strict rules about cylinder heads at that time, and hacking one up from a different engine and using it wasn't in the low-budget spirit of the rules (for M/P.)
At least, that's the way I remember it.... which proves nothing....