The difference is stated as only 1/4" (roughly) in length so It seems not too difficult a task to make an extended pilot bearing out of oil impregnated bronze on a lathe. The diameter is smaller but again if you are making it on a lathe from bronze stock, no problem. BTW, my T-5 is from my '88 Turbo Coupe that was for 10 years my Daily Driver. 150K miles and still getting the job done.
Trans swaps always seem to be talked about with terms like "just" but that word often has significant limitations. There is a Toploader from a 80-86 Jeep pick up I've been trying to find for my Sunbeam Tiger called a T-178. It seems a very rare item to find. And strange because most Jeep guys want the granny geared T-176/177 so you would think the T178 would be a "get rid of" item. Another trans the R-154 from Toyota (Supra Turbo) is a very stout 5 speed but I've never found one. These have adaptations to AMC and Chrysler (Plymouth-Dodge) products.
So, I'm always cautious when dealing with (advising on) these things. Today it is hard to "just" find a 2.3, T-5 and "pop" it in a Pinto. One must acquire the: flywheel, pressure plate, disc, throw out bearing, clutch fork, bellhousing, cable, pedals, adaptation to the cable to trans mount, cutting the tunnel, shortening/repositioning the shifter, altering the trans mount, altering the drive shaft --- and THEN you can "just pop" in the now difficult to acquire trans. I would just not feel it is right to encourage someone along who either has no experience, or has a history not completing projects. Call it a sense of moral responsibility . Ultimately it is up to them to decide and for some they can rise to the challange, but being on many car foums I all too often see regression instead of progression. Sad for the owner, sad for the car.