I'm also on the 'confused list'... And, really curious. Wishing Pete would elaborate a little, if indeed, an 8ba crank in an A block (and, I mean Model A). And, is this what Alan had in mind?
I think a lot of relative new comers may think of a 59AB as a A block when there are several possibilities to describe a flathead. To begin with, in the Ford and Merc line they are either 221ci 21 stud or or 221ci and 239ci. 24stud blocks. To my knowledge the 24stud mains are the same diameter up to 53.
In my mind, it was not called an 'A' block - more along the line that it is a 221 CI Ford engine with a 3 1/16 bore - with a variety of heads (some of which had the big letter 'A' on them). There were other heads that did not . . .
Also, you will need to change the rear pot metal slinger/seal plates - to the later ones with the rope seals) - as the 39-41 blocks used an earlier slinger/labyrinth type of seal.
have done this before but not in a long time, still have the pot metal slinger from joblot's reproductions. just need any know reminder, yes block was bore to 3 3/16. bored and stroked--sorry your mind id different than mine, as I always referred to this as an A block
"Commonly"? Where is a 59A block referred to commonly as an 'A' block? But what the heck, I've no doubt missed lots of things during my 67+ years in the hobby.
81A for 38-40 221 with 24 studs. 99 or 99A for early 239. The 11A block was when they changed the castings. The 59 series also included the replacement 41A for 221 engines but many have the 59 casting mark as well.
The Big A heads were just the 81A heads. Prewar 24-stud 221 block pretty well says it all. When I think A and block put together, I think Model A 200 CID 4-cylinder block.