59A vs. 59A-B Cylinder Head Interchangeability?

[Ford1941]

Are there any actual functional differences between a 59A and 59A-B cylinder heads? Could a 59A and a 59A-B head be used together on the same engine without creating any problems? In other words are they totally interchangeable?

On a separate but related note, when would you have typically found the 59A-B heads used vs. the 59A heads during the 46 - 48 model years? For example, were the A-B heads used later in the model years, or as replacements?

Thanks, Scott

 

[Fred A]

Not Totally Interchangable

The heads on my 59A engine were mixed and with all the other approximations, the heads were the least of the the functional problems. It ran well enough, but they are slightly different. Seems that identical heads still have one side with more compression. One way to describe why there are two '46-'48 heads is that a clarification was needed between the right and left head, so the A-B replaces two part numbers, XX-6050 and XX-6051. Seems that the A-B came later. Good Luck: Fred A

 

[Bruce Lancaster]

A was early production, AB was later, I do not have a date for that but most '46-8 Fords seem to have AB.
59A-A spec is 77-79 CC, 59A-B is 73.5-75.5, 5 pounds higher cranking pressure spec. I don't have the parts book in hand here, but I believe they suggest replacing both heads when buying a new head...only the B version continued in stock. It would not hurt to check your actual chamber volumes before changing anything, as specs are known to wander a bit...