You could say that. In my opinion the op doesnt have to cc the heads. He or she should be able to check the part numbers and verify what the chamber size is and if they are the same they should work. There are stories of the factory running two heads one with a U on it one with a J or O etc. For the OP to cc the heads and come up with .4 of a cc variation then what come here and have you all blow more smoke up his ***? c mon man...that's a whole 'nother issue the variation in the casting of the combustion chambers.. You all are just giving the guy the runaround and it is unnecessary. This is 50-60 year old automotive technology it isn't rocket science...OP, check out this thread, Look up your casting numbers and Combustion chamber size with the chart in post #8.
Combustion chamber CC's Chart ??