My motor is smoking!

Sorry to hear about your problems after you just went through all the trouble to put some good heads on there. When you had the heads off how did the cylinders look? With 30,000 miles those cylinder walls should have looked like new. You should have still seen the cross hatch pattern with no lip at the top. We know the heads you used to have on there were not rebuilt but maybe the bottom end was? I'd pull that intake and see if oil is in the intake ports of the heads. If so then you are sucking oil in from the intake to head gasket. Worth a look. Could be intake gasket and now oil is laying around in the exhaust causing lots of smoke.