Hot Rods Flathead head swap

Putting 59ab heads on an 8ba block. Is there any reason other than appearance? Do they cool better?
Reason is I have a 8ba and a set of finned 59ab heads.

Jim

 

You will have to plug a couple of water p***ages in the block to run the early heads

 

There is a steam hole(s) on the 8ba block that will have to be filled. I personally like the looks of the 59a heads, but I believe the moved the thermostat forward on the 8ba for air bubbles less likely to be trapped and keeping temps down.

 

I knew about the plugs. I just wondered if other than appearance if there was anything to gain in the way of performance or cooling.

 

Actually you will probably hurt cooling performance. Ford enlarged the water jacket holes at the back of the block (and the heads to match), and if you put small holed early heads on the larger holed late block you will be slowing the flow. Henry must have wanted the bigger holes for a good reason.