Next is a bottom end shot of a 336. For those who don't know, the 336 was a small bore version of the 347 used is GMCs. Note the strenthening rib that runs the length of the block like the SDs and Ram Air Vs. Few Pontiac people know about this (you're welcome). 1955-early 1960 is similiar.
Steve
www.pontiacheaven.org