Oil Filter Adapter
I do have TTI headers, and the thin bolt head almost touches. I bought a Fel-Pro gasket set and a hardened replacement bolt (all in a kit). The new bolt has a 1 3/16 diameter washer head under a 7/8 hex head. It’s a little thicker and stouter than the thin original 1 3/16 hex bolt. We’ll see what kind of clearance it gives.