Early 904 to later slant six conversion.

Im putting an 81 225 into my 62 Valiant.
I understand they WILL go together, but the OD of the tq converter nose is significantly smaller than the tail of the later crank.
The flex plate should not be relied to take up the difference.
I heard someone makes a “bushing”?
I don’t know who….
Can anyone give me the dimension of the outside nose of the early pushbutton 904?
Anything I leave out?
Early or Late flex plate?