The bellhousing and intake bolts are the same size: 3/8" - 16 x 1 1/4" long and both have a flanged head. Including your input, I've heard of heads with 3 slash lines and either A, B, C, L, M or P in the center. It looks like we're getting closer but it still seems somewhat of a mystery. I wonder if there is a member with an unmolested V8 survivor firebird. Thanks for taking time to look!!
