383 new rebuilt starting issue

So SIXTEEN days later and you're still crappin around. Pull the engine and tear into it. Something isn't right. It's not gonna fix itself.
I understand his reasoning. Would hate to pull an engine only to find out that your inspection cover was hitting flexplate bolt. But if you’re finding metal in the oil it has to come apart .
I have spent the last 3 weeks trying to isolate an engine vibration in my new 408 . Changed pinion angles umptine times , rejetted same , 3 distributor curves , compression checks etc . Nope …. Balance job is wrong . Pulling the engine now and machinist is going to rebalance . Urghhh