[Jeff Lee]

For what it's worth, probably zero, I had a '69 Mach 1 in high school. It had a 4-speed and 3.25 gears, headers and a Holley 700 DP on the 290 HP 351W. Nothing else altered from stock except high-tension points. I never lost to a Clevland. Had to prove it's Windsor status more than once. Pulled 6500 RPM (per factory tach) all day long with fresh points.
The Clevland guys never could figure it out...