Help with camshaft for 340/416

fratzog lover said
Gonna take more than a guess on compression. Cam duration needs to know the CR spot on. The car I bought had paperwork from the previous owner. I found him in Ohio and called him up. One question was CR. 9.5 replacement pistons he said. So I order a 268 cam. Turns out 8.0 was more like it. Not that it was a complete dog, but far from what it should have been.

dartfreak75 said
It's not hard to find out. The engine is out of the car. Your replacing the heads so look at the cc on the new heads (combustion chambers cc) then measure how far the pistons are in the hole. Cc the piston tops If they are flat tops with relief cuts. The figure out what gaskets your gonna use and plug all that info into a compression calculator I like this one. Engine Compression Ratio (CR) Calculator

ya that was my plan this morning pulled the heads to find some substantial scoring in the cylinders not sure what went on here as I bought the car with the motor in it. Needlessly to say pretty bummed out. Going to take it to the machine shop to see it it can be fixed, I’m suspicious they are too deep.