Sixty cylinder jugs

Question I have is are they all the same or do they need to be kept together as sets?  See some marked 14A and some have a B casting, any differences internally?  Same question reguarding the heads, are there different ones out there, certain ones more desirable?  Starting in working on a stuck Sixty project and trying to figure out my parts options. Thanks, Mike 

The Sixty Parts Catalog. Form UE 5451, only lists two cylinder assemblies: Part # 2475-A and 1A4164 (6 3/4" bore).

There are 3 cylinder head assemblies listed: 2329-A, 1A926 and 1A1257 and 1A1258. The 1A1257/ 1A1258 assemblies uses 3 3/16" valves.
For alignment purposes probably should measure and be sure that both intake and exhaust manifolds will be aligned.