Series III Compression Ratio

[edscripps]

I would like to verify the compression ratio on my '74 series III, the engine number which begins with 904 indicates it's 7:1, but I was told the best way to confirm was to look on the cylinder head and the compression ratio is stamped on the side. Does anyone know where? I can't seem to find anything that looks like #:#.

Thanks,
-Ed

[rover_chump]

Greetings,

Look on the top of the head, between the carb and the manifold (you should see a square block ... about 1" x 1" ...if it is an 8:1 it will have an "8" stamped into that block...you may have to wipe away some grease to see it, sometimes it is stamped lightly. If it is a 7:1 it will have a "7" stamped in the block..or...the block may not even be there)
If it is the original head....I would assume that its 8:1
Head thickness.... 7:1 = 3.69" 8:1 = 3.59"
Peace,
Art

[LH Drive]

My series 3 has the 8:1 head and the stamped 8 looks more like two zeros side by side.

[Leslie]

I thought that by the SIII, they were all 8:1; my '72 is an 8....

On mine, the 8 looks more like gull-wings, as if the 8 were only stamped on one side....