Chased the block threads with an an head bolt. Turns out the BBC block is 7/16 by 14 and my taps are 7/16 by 13. Mucked about with some play-doh...pretty sure I would fail grade 3 art class. On the plus side my valve to piston clearance appears to be good. No HG and head bolts tight but not fully torqued.
Used some Permatex copper spray gasket on the head gaskets... figured it couldn't hurt. Heads are torqued down to 75ftlbs expect for the 4 short bolts that get 65ftlbs. Waiting on my torque convertor fluid to arrive. Once that's here the engine can go back into the truck.... Progress of sorts
