rebuilt 360 oil loss HELP!

I have seen this happen when the intake manifold gasket did not seal off well and it would suck oil out of the engine to 1 or more cylinders. This will usually cause a rough idle (vacumn leak). Also would check the PVC system, if aftermarket valve covers were used make sure the shield has been installed on the PVC side. If it was this though it would probably smoke out both exhaust. Good luck.