Thanks for steering me to Patrick. I got to talk to the man himself. He says DO NOT put the 1/4" size plug in. The oil passage between the two thread sizes feeds the cam & rear main bearing. He said he can't remember seeing the 1/4" threaded "inner" hole on a block before. He seemed to not be familiar with that. I don't know if I have an oddball block or what. I'm going to follow Patrick's advice & put the engine in. I'll post results when i get it running.
