Bought my First Mopar

So I bought a 68 valiant 4 door for 1500 bucks. Great way to get into mopar i figure. Few questions because I'm new here.

The guy I bought it from put a Pro Comp cam in it, Lift .3026, duration 218

He also said it was bored .030 over.

It runs ok but when I crank it, it sounds like it has no compression. I checked compression and had 75 to 100. Seems to low to me. Also there is a terrible valve tap.

Is the low compression a result of the bored cylinder and/or the cam? It runs really well other than it cranks a lot to start. Also you can smell a lot of raw fuel in the exhaust.

I know ... what do you expect for $1500? Just getting an idea of whether i should mess with what I have or just do a 318 swap.

Thanks