You will need to do a search for a compression ratio calculator on google. FYI chevy 350 is 4.0 bore and 3.48 stroke stock.
Big car with gear and good intake/exhuast for low compression I would go with the edelbrock performer or the performer rpm if you find out you have high enough compression to run it.
Edelbrock could help you get the setup with the right stuff. Just give them a call.
You have got a massive amount of choices for cams. Edelbrock has shorten this down to a few good choices. Makes the selection easier.