Sorry, but I don't understand your thinking, you drop a motor in without even replacing gaskets, turbos.. I imagine you learned a lesson or two.. Get a qualified mechanic who will steer you in the right direction. Any good Z specialist, would of warned you to do the maintenance on your engine before dropping it in. Now you have an oil leak?? Either front crankshaft seal, or oil pan gasket.. You live and learn, the hard way for some folks.