make sure to check the intake without a gasket so you know for sure about any spaces etc. also, make sure the gasket is installed right becaus those rear ports are sometimes covered so the coolant flow goes the right way without short cutting.
other things to check
-pcv valve and baffled cavity in valve cover under the pcv to make sure it isn't sucking oil in that way. some aftermarket covers don't have much for baffles under there.
-auto trans vacuum hose (if equipped) to modulator valve. if modulator valve is leaking the engine can suck up trans oil.
-document how much oil is being used. check it the same way every time-like if it is hot and just shut off or, if it is hot and has sat for several minutes so the oil has had a chance to find it's way back to the oil pan- making the level higher than if checked right after shut down.
-make sure it is engine oil and not trans fluid or coolant.
-pressure test the cooling system to make sure you are good to go there. did you flush the rad etc before assembly was finished? is the core clean on the inside?
-are all the plugs burning the same as far as what colour they are when you take them out? a dark plug can tell you that cyl is getting oiled or fueled more than the rest. make sure to have the proper reach on the plug and correct heat range. too long of a reach can cause hot running, as can too hot of a heat range.
keep us posted.