WHY low vacuum on freshly rebuilt motor?!

8* seems low. Try 12-16* initial in increments. If your low end and vacuum does not increase, I would venture to wonder if the cam was degree'd in wrong "retarded". Did you degree the cam or just go dot to dot on the gear marks when you installed the timing set?

Unfortunately i had a family member that is supposedly a mopar gear head assemble the engine. I assumed the timing marks were lined up but have no idea. What cam would you guys reccomend with the pistons im running?