904 questions - where is my 904 experts

Thanks Guys.
The trans was rebuilt already -300miles and the need for more stall is forcing my hand on the input shaft after the engine was taken back apart to open up the crank shaft.
I really don’t want to change the trans out with newer…. Not because I don’t recognize the complete benefits but I recognize the cost associated with rebuilding another 904 and the chances a 66’904 rebuilt will ever get used again is slim to non. I’m just trying to make what I have work after the fact (a well rebuilt 66 a-904)