This is the original head off the 455. I cc’d the head using a piece of plexiglass sealed with bearing grease and the syringe shown in picture. Repeated the process 4 times and all 4 times it came out to 68 cc’s. I read on a site that gives specs for various year buick heads that the 73 heads are 71 cc . 1968 430 heads are listed as 69 cc. Other than the difference in intake port size and the additional cast in port for smog gases in the 73 heads they both look very similar.The combustion chambers for both year heads appear similar in that they are both closed chamber. Any idea where the discrepancy may lie? Im thinking I may use the 455 heads.
I believe the discrepancy is in “specified” chamber size and “as cast” size. Tolerance stack up during the mold setting, pouring, cooling processes.
