There is no supercase 904 or 727. Reid makes superglide and turboglide case which are gm based transmissions.

However, A-1 makes an adapter that allows cutting off the thin bellhousing at the pump and bolting their part to the pump. This allows you to bolt any Reid pattern bell which are blow proof.

Reid, BTE, and QuickTime all offer bells using this pattern.

I offer the bells and adapter ring for this application.which is popular with the R5 nascar engines.