Still in the scheming/ducks in a row stage of planning. So I have this T18 with a 6.32:1 first gear that came out of a 79 CJ7 and was considering swapping it into my YJ. The YJ was set up for an automatic, but almost everything else would be a bolt in affair (I've also read that Automatics had the 23 spline NP231s, but until I see it with my own eyeballs I'm not taking anything for granted anymore). Advance Adapters makes a T18 to NP231 adapter kit and it adds 3.25" inches to the T18 which is a little under a foot long. My question to the people who have done this is did you use a stock driveshaft or have to get a custom one?