Auto trans input shaft/TC hub vs crankshaft register

It's just a matter of budget. This is a stock engine and trans. The transmission is good but who knows for how much longer (no history of the transmission was available when I bought the car). If I got the new converter and then the transmission goes out in a few months then I have to have that one rebuilt and there are few shops where I live and none that I would trust. Then I'm stuck with a converter I cant use on a 27 spline transmission. If I use the bushing and the transmission goes bad then I'm out just the cost of the bushing. Then I would save up and replace the transmission and converter with the 27 spline input and large pilot but it would take a lot longer than I would like. Believe me I would really like to swap it all properly right now but just don't have the funds. Just trying to buy some time. Hope all this makes sense, feel like im between a rock and a hard place. Thanks for passing on some great info that I knew nothing about.
I totally understand, been there before. Good luck on finding the bushing, and you're right, no sense getting a converter built and then find out that the transmission goes sideways on you down the road.