Topic: 1970 351M code - 11.1 compression

[Shelby1962]

How is the drivabilty with the 351M code hi-compression with today's fuel? The prior owner (22yrs.) always ran racing fuel and kept a log book every time he drove it. The engine is totally stock.  Haven't been able to drive the car yet because of the snow on the roads. Manual states 100 octane, seeing that is not available I'm concerned about detonation. Is 93 sufficient with lead additive? 

[ClevelandKid]

My 70 Mach1 M code 351C 11:1 compression 4 speed car runs fine on 93 octane gas. I don't get any detonation at all I think 3:50 or lower gears helps. Mine has 3:50 gears. My engine has 75,000 miles on it and I have never had it apart. I've owned it since 9/73. I run a few degrees timing advance too with a Pertronix Ignitor 1 and a Flame Thrower coil. The car runs like a Swiss watch. I think running 100 octane racing gas in a street stock engine and all the other additives is just throwing your money away. Just my 2¢.