727 Converter Question

I am not to versed on torque converters.

I have two converter a friend has given me.

One has a small diameter pump drive. I "ASSUME" this is a 904 converter.

The one I have an interest in has a larger diameter pump drive. I "ASSUME" this is a 727 converter.

I do not know if it is from a small block or big block 727.

It does have a small about 3/4" square sheet metal square tab spot welded to the case.

That kind of leads me to believe it came from a external balance engine.

Can this converter be used behind my big block if it is from a small block.

If so, should the spot welded tab be removed.

I want to replace the COAN Billet 3800 stall with a more street friendly converter.

Thanks,

Herb