.40 over 170 rebuild

A photo or the specs from the card will be helpful.

Yes, the compression ratio and cam should work together. You can run more compression with a bigger cam. With a real mild cam, you don't want too much compression, or you will need premium fuel. It will also be harder to get a good usable timing curve. If you don't have much experiance, I would suggest staying about 9 to 1.