Break in with TTIs

Yea we finally got them on, Turns out that the engine was jacked up to high and tilted to far. Once we dropped the engine, they slipped in perfectly. thats what i thought and was hoping for better news, I'd rather take the extra time and break the engine in right then mess up my headers. We have manifolds but no exhaust system for them. LOL wonder how loud bare exhaust manifolds would roar for 20 minutes???