The 904 version with OD is an A500/42RH, there is an electronic version but you don't want that one.
The 727 version with OD is an A518/46RH, same thing on the electronic version.
The A500/42RH will have a lock up convertor which is not desireable for performance applications. But will work in street/mild strip applications.
You can get the A518 in both lock up and non-lock up versions. I have a non-lock up version I took out of a '92 B350 van.
The 904/A500/42RH is pletty capable in a small block application.
Chuck