Inspection of a 904 torqueflite

Can I get a newer sun shell with the 2.74 gear and planet and just set it in there with no other modifications

I would rather lower the gear in the transmission than the differential. I guess I could just get it and see how it goes. I know they sometimes match to the 5 disc clutch and a different pump.
But I also see the hp trans shops selling them as standalone upgrades. My car runs a 2.73 gear set and I would like to keep that. If you guys know for sure. I would like to know. I’ve researched the hell out of it and find all sorts of information where people have run this....but nothing definitive. Nothing that says....yes it works and this is how.

Basically like the ones in the picture
48111891772_1362bfc47c_z.jpg
If I put all that in my 904......will it work with no other modifications. -