1966 Ply Belvedere

[OLD GUY]

Originally Posted by Grey Ghost

Is that specific intake manifold required or can the "street" version be legally substituted?

The 2780543 and 2780544 are one and the same Street Hemi intake. For some unknown reason Chrysler saw fit to have 2 casting numbers on the Street Hemi intake. As far as I know all Street Hemi intakes have those two casting numbers on them. So to answer your question the 2780544 casting number is just one of the two casting numbers and not a separate number for a different design manifold.