Recently built a 302 for my Fox. Completely rebuilt. First time we fired it up, no oil was burning. When we hooked up exhaust, it started to profusely burn oil from the tailpipes. I think that the exhaust (which is brand new) is the culprit. Would there be oil left inside the exhaust system from manufacturing? Or are the band clamps (which I'm pretty sure have rubber on them somewhere) causing some issues? Please help!