[tubman]

I think the first thing you should do is determine exactly which early engine you have. There is no such thing as a 1941 59A. The "5" designates the year of introduction, in this case 1945. If it is a '41 engine, here is a good chance that it is a 221 ci rather than a 239. If it really is a 59n (there are a bunch of varieties), it would probably the best choice if both engines are in the same shape. You should also be aware the the pre-'49 engines have full-floating rod bearings, which can be hard to find, expensive, and difficult to fit. Unless you already know the condition of both blocks, the first thing you have to do is disassemble them and do some preliminary crack checking. You decision may have already been made for you.

The way things currently work out, you will be lucky if even one of the blocks is good.