904 questions - where is my 904 experts

So in that 66’ barracuda with the heavily modified 273 I finished a bit ago. I decided to pull the engine back out after 300miles and get the back of the crank turned to accept the larger 904 converter nub (machine shop forgot to do that when they built the engine but they are making good now it’s winter) and now I need the input shaft replaced in that 66’ trans.

On the 1966 904- factory to my Barracuda when I replace the input shaft to the 27 spline, so I also need to swap the pump and the front clutch retainer or is it just a swap of the input shaft? I’ve read thru hours of search questions and I’ve yet to see anyone talk about it other than suggestion of it. It’s not hard but I’m trying to pick what donor tranny from my pile to use and the more I need in parts the less options I have lol! Some are smoked. LOL!
Thanks!
Joe