I pulled my 304/T-15 a few years ago. Pretty easy swap, call Advanced Adapters and get the scoop and parts directly from them. They've got it all and are the supplier for most of the parts houses. You'll need motor mounts (AA has bolt in or weld in), bellhousing (depending on trans/engine combo), and trans/transfer case adapter at the least. More depending on parts selection. I'm running a warmed over 350 with a NP 435 4-speed and a Dana 20 transfer case. I mated the trans to the 350 using a stock chevy mid 80's hydraulic clutch bellhousing and aftermarket clutch assembly. Used the stock Jeep (4 cly Iron Duke engine) clutch master cylinder and chevy pickup slave cylinder. NP 435 to Dana 20 'case was AA and dropped in 3.15 low gears while it was apart. My axles are Dana 44/Dana 30 with Detroit Locker and 4.27s. Gear carrier and gears will work in either axle housing. I like the gears, a good compromise between crawling and the occasional highway ride.
'45 Ford GPW; '73 CJ5, 350/NP435/D20 w/Terlow gears, locked D30/D44; '13 CJ8, 304/T150/D20/D30/AMC20 w/locker and limited slip (T18 and Teralow gears in future); '88 Dodge RC, 360/NP435/NP205/D60s