Help with 340 compression + cam change

The 351M in my 75 F250 had 160-165 in all eight about 5 years ago when I put the re-man heads on it. They are rated at 8.4:1, but routinely spec out at around 8:1. The cam in mine I am almost positive is the Melling, Elgin, everybody's grind that's like .486/.512 and 204 and 214 ground on a 112. It has a very slight bump when cold but stock when warm.

Your example is a shining one that all the formulas and calculators in the world sometimes come up short. Did you degree that cam? If not, you can add a good chunk to it if you advance the camshaft timing probably 4*. I have threatened to do that with mine, but I have the rebuilt 400 under the work bench.