Got the big block shoe horned in....
Art imitates life...the ill fitting kit headers put up a fight....pulled the engine back out and repositioned the front half of the right side header...fits better....not perfect,just better.
The kit engine is rather unique....the block most closely resembles a Ford big block (429-460) but the kit has both the 351 Cleveland high port heads and valve covers and big block heads and valve covers..... I went with the big block heads, duh
and valve covers. I ditched the box looking intake manifold and went with a resin cast stock big block intake since the rules back then stipulated cast iron intakes. Also ditched the cowl induction air cleaner and dug something out of the spare parts box. Removed the alternator and bracket and added a belt section to the pulleys. Scratch built two oil breathers for the Left side valve cover.
All I have left is installing the radiator and hoses and the fan shroud and this build will be DONE.