Late Model and Early Model Heads
 

I have tried doing searches on here and I have a couple of questions that have been on my mind.
I have seen pictures and engines on Craigslist that use the opposite style heads, Early block with Late heads or Late block with Early heads. Is there anything wrong with doing this, as far as cooling efficiency? I mean the early blocks have larger water ports in the center while the late blocks have the larger ports at the front. Wouldn't that cause a restriction? I'm talking like the 40 - 51 blocks and heads.
Also, what block had better cooling? The early block or the late block?
Just something that has been on my mind.

Re: Late Model and Early Model Heads
 

To me it is obvious that the correct head for the block is the best way to go. But, that being said, people have been switching them for years. There are some fairly minor modification you need to make to the water passages and you have to use the correct gasket for the combination you are using. I'm sure these combinations don't flow as good as the original head on the engines, but they work and it has been being done for years (most likely from the time both style heads were available!)

Re: Late Model and Early Model Heads
 

Re: Late Model and Early Model Heads
 

With the convenience of an easily adjustable/ maintainable distributor!
I'm running early heads on my 52 Merc motor , only mod I remember doing was plugging the Extra hole in right front of block deck.

Re: Late Model and Early Model Heads
 

I guess another reason why I was wondering about this is because of something I read online. There was an article that said Ford moved the water outlets to the front of the block to help with the cooling. To me, I'm not an expert, that seems like it would prevent coolant from reaching the back of the block. Or is there some other design inside the water passages that help circulate the coolant all the way to the back?

Re: Late Model and Early Model Heads
 

Yes, Ford did allot of research on this changing the flow as well as the pumps to some extent, However if you use the gasket tha come with the head and not the bock it usually works just fine, been do too many times to count.

Re: Late Model and Early Model Heads
 

The water passages in the deck were revised for the 8BA style blocks. The passage toward the front of the block are small and the passage at the back are wide. This forces a lot of water all the way to the back of the block, then returns it the length of the head. Most of the cool running flatheads I have seen are 8BA style. You can see the differences in this post http://www.fordbarn.com/forum/showpo...4&postcount=15.