IMO no, if that was an 8:1 engine I don't think you could pull 20 inches with it. I'd honestly expect more like 17 inches with that cam, but you've got your initial timing set pretty well assuming the mark is right. So its possible, I'd just expect less. More is good if you do have the right cam, just wondering if they put a sealed power lo po cam in or something. Really its neither here nor there, because it would still run better regardless.

As has been said run the cranking compression test. It doesn't mean anything if its high, but if its low you have problems (I know sounds encouraging doesnt it?). And get the 02 in. Do you know anyone with a carb you can borrow?

One more question, you DID unplug the vacuum advance when you set the timing right? And did you verify your total with the light, or assume it to be correct based off of the info on the distributor?