I have heard there is a difference in the 226 48 -51 H heads .

I have a 8HA , 0HA , and a 1HA head but they are on the motors so I can not see the combustion cambers . Is there a difference in cc's ?

I also assume that the G series heads (41-47) wont work on the later motors ?

 

My memory is that all H heads have the same combustion chamber and compression ratio. The M head has larger chambers. The G head may bolt on and work on an H engine, but the combustion chamber in the H head is a better design.