In searching for information on what needs to be done if you want to run 59ab style heads on an 8ba I never really was clear in what holes needed to be plugged. I talked to some folks and they mentioned that once you put the ab gaskets on the block, you'll know right away. I figured I would post pics of what I did to what holes. In gathering info, there are 2 holes in the block and one in the head. The two in the block are up front right by the water pumps. You will need three 1/4 pipe plugs, the countersink kind that use an allen wrench. The holes in the block just need to be tapped, there is no drilling required. The head will need to be drilled and tapped. Here is a pic of me tapping the left side if the block to accept a 1/4 pipe plug. Tapping a cast block is fairly easy and does not require a lot of pressure. Here is a pic of the left side once the hole was tapped and the plug inserted. I used a brass plug and sank it about 1/16th of an inch below the deck so as not to interfere with the head gasket. You will want to tap the right side(passenger) as well in the same way. Its the front middle hole that is right behind the water pump. Make sure you use a waterproof thread sealant on the brass plugs as well. This should prevent against any leaks - Fryguy
Onto the head. You will need to drill and tap the drivers side head as well as the front center hole does not line up directly with the hole in the block. I am using Navarro Aluminum 59ab heads. You will need a 7/16 drill bit and a 1/4 npt tape(tapered pipe) and some sealant Here is the hole circled on the head, it sits between the two stud holes and does almost line up with the hole in the block that we just plugged. You will need to drill the hole out with the 7/16 drill bit, clean it up with a small file if need be. Then you use the 1/4 pipe tap and run it through the hole. Use a bit of cutting oil if you can, it will make it a little easier. One its tapped, you can use a small file to remove any ridges create when you tapped the hole. Make sure you blow out the head as well as you do not need any small aluminum chips getting in your chambers. One you have it tapped and clean, you can use a little pipe thread sealant on the brass plug as well to prevent any leaks. You should install the brass plug about a 1/16th of an inch below the deck surface of the head as not to interfere with the sealing of the head gasket. Hope this helps anybody who wants to run the AB style heads on their 8BA block.
Very well done. This is a common procedure but it always seems to instill fear in those wanting to do it.
I'm thinking of doing the same. Thought it would be straight-forward and you proved it. However, can the fuel pump from the earlier engine be made to work on the later engine? Also, what about the road draft tube/breather issue? I want this thing to look as close as possible to the earlier style.
I am curious also about the heat issue. Anyone know for sure if this would not cool as well as the "correct" heads? Living in Texas has me wondering if this would be a good idea for my build.
I see there a few questions about cooling issues. I personally have not started up the motor yet as its a replacement for my 37 21 stud. This actually is and has been done a lot of the years and I am definitely not blazing a new path. I am not sure if there are any major cooling issues in using these heads on the 8ba. In searching for info there was always talk about blocking of the water passages but I was never able to pull up a walk through. I thought it a good idea to post pictures of how I did it as I know many others are looking to do the same thing. Maybe there will be more posts from others who have done it as well and they can chime in on their cooling issues.
Thanks for the post! It must work from a cooling standpoint because there are numerous engines out there running the early heads along with a later block.
Just because it has been done, does not mean that the engine cools as well as it would without blocking off cooling passages. Also, engine operating temps could vary greatly between South Dakota and southern Texas in the middle of summer. That is the reasoning for my question. If anyone has first hand knowledge, please chime in on this great tech thread. Thanks.
I realize this is an older thread, but doing my French block right now. Pass side is done, but the drivers side head gasket sits right over the hole that most are saying to plug. Am I missing something? I am using the Felpro 7525/7526 gaskets for 8ba, just trimmed the pass side up front.
It seems some are concerned with the efficiency of the cooling system after this mod is made; They should consider that the redesign of the heads (including moving the outlets to the front of the heads) and size and location of the water passages in the block was done by the Ford engineers to improve cooling in the new 8BA series of engines.
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