90 degree adapter leak

Finishing up my first project, 360 commando into my 1969 dart and can’t stop oil Leah at the bolt head. Tried various gasket kits from almost everyone who sells them, including a new bolt as well. Tharen the adapter of and even filed the surface the bolt tightened to and still leaks.I don’t see any evidence of the housing being cracked. Am I missing something to mounting the adapter?