B1 cast single 4-barrel intake manifold with RB spacers.
Not too much to say about this. It appears the previous owner cleaned up the plenum and the runner openings, but I don’t believe it is significantly “ported”. The RB spacers look like they were never used, so they will need to be matched to the intake and heads. I machined them almost to the size of the heads and intake, which are basically the same size. The openings on the heads (CNC) are 2.740” x 1.755” , divider 0.250”


I have done a preliminary mock-up with my block, head gaskets, heads, 0.060” intake manifold gasket on 1-side of the RB spacers, and a 0.030” intake manifold gasket on the other. The intake manifold dropped on nicely, the port alignment is close, and the B1 valley pan bolted to the block and head with no problems. So the previous owner of the heads milled them “correctly”. I will do a hand blending (air die grinder) to finish the RB spacers.