The bolt pattern is SAE #4. Most were manuals, but the IH 727 was available. Though from what I've read, making the linkages work was/is an engineering feat, so IH didn't produce many of those combos. Trying to compare the 22 to the 33 is like apples to oranges. The 22 is a 4cyl, the 33 is a 6cyl. I don't know if the 22 ever came with a turbo, either.
These are great engines, but they are becoming harder to find. That's the main reason I'm not switching to one in my Scout. But if you have already sourced one, use it! Anyway, you should have plenty of room to fit it in, as it's about the size of a 4.0 J**p motor. T-cases were mostly Dana 20's, but IH went to the Dana 300 for the last year, 1980. So either can be had. The T-19 seems to be a popular trans for diesel Scouts.
Here's some quotes from the binder bulletin about the 33:
A total of 10,719 Nissan Diesel powered Scout II's were built from 1976 until the end of production in 1980. 4222 non-turbocharged (SD-33) diesels were used in Scouts from 1976 thru 1979, and 6497 turbocharged (SD-33T) Diesel Scouts were built during the 1980 model year. The diesel option was available in all models except the SSII.
IH used one diesel engine in the Scout II. It was availible turbocharged in 1980. The diesel engine is an inline 6-cylinder that displaced 198 cubic inches. Its bore is 3.27 in. and stroke is 3.94 in. The compression ratio is 21 to 1. The standard diesel produced 92hp, the turbocharged version produced 101 hp and 175 lb/ft of torque. These aren't stunning engine numbers, but these diesels are very reliable and get decent mileage.
Here's a power graph:
While these numbers are not what some would consider "stellar", the SD33 family of Nissan engines are very reliable, strong, and ask for little in the way of maintenance. The engine uses industry-standard BOSCH injection system components (license built by Diesel Kiki) and is known world-wide as a reliable, long-lived powerplant.
As far as performance, all I can say is this; my friend Carl Wiese has a turbo'd 80 Scout Traveler. This rig probably weighs in at about 5500#, as my standard Scout 2 is close to 5k. Anyway, he has propane injection on it, open exhaust (and it's very quiet actually!), and an "elbow eliminator kit" to free up a restriction in the factory exhaust. I think he's running 3.55's and has a close ratio T-19 in it. All this to say,...
it is quite peppy. Not a neck snapper by any means, but it has impressed me on several occasions.
If you really need to get into detail about the SD's and their capabilities, go to the IH BB and talk to my friends. John Donnelly is a great guy with an inmeasurable amount of info in his memory banks alone, or talk to Carl. You can find them on there by their names, no secret usernames for them. But be sure to look around the site first, anything you might want to know has probably already been addressed.