Quick question, is a 21 stud a 59ab engine or an 8ba engine. I may have found a "21 stud flathead" near by. What are the differences between a 59ab and 8ba? I know I want a 8ba because I've heard thy're a better engine, with some upgrades from the 59ab, but is a 59ab that bad? What should I be looking for when examining the engine?
Thanks for your help.

 

Not a flat head expert by any stretch but here is what I know.
The 21 stud was used before the 24 stud engine which came out in '38.
I don't think the 21 stud is what you want.

The 59 was used 39-49. The 8BA was used 49-53 in cars and 48-53 in trucks but designated 8RT in trucks.
Their are several differences in the two but both are good engines.

The 59 has the flywheel housing as part of the block where on the 8BA-8RT it is bolt on. The water outlets on the heads are in the center on 59 and front on 8BA-8RT.
There are other differences but these are obvous when looking at an engine.
Heads can be switched so flywheel housing is best identifier.

A lot of info here. Ford Flathead Specifications

PS
Flathead blocks are prone to crack and goods ones are getting scarce.
It would be wise to get someone knowledgeable of flatheads to check one out before gettting much $$$ tied up in one.

Hope this helps a little.

 

There are a couple of versions of the 21 stud flathead block. The early blocks 32-36 have the water pumps that bolt to the heads. The 37 and into early 38 had the waterpumps in the block like the 24 stud motors. The 36 LB blocks and the later 37-8 21 stud blocks had insert mains while the earlier 21 stud blocks had babbitted mains.

 

If you need a good 8BA/8RT block, I know a source who is selling inspected, vatted blocks for $500, delivery available if you are anywhere along the front range (you haven't got your location in your signature). Worth it to know what you're getting. I wouldn't mess with a 21 stud, just no reason to.

Anyone else interested, he has about 20 more blocks, delivery in February.

 

All great information, thanks. I thought I had found a really good deal. I'm glad I didn't jump on it. It is amazing where a little knowledge will get ya.
Albuq, I may be interested in a block. I live in Petaluma, CA. Any more info would be great, thanks.

 

Send me an email, I can't send one to you.