You cannot use the t18, clutch parts or bellhousing from the 4 cylinder application. The clutch pivot assembly is wrong too but it is possible to somehow make it work. I recommend you find a rolling v8 frame and fit your Scout's body to that frame. you have to do it anyway, and a v8-into-4 cyl Scout operation is challenging, expensive and time consuming, even if you are up to the technical aspects of the swap. The engine/transmission swap is only the very first in a line of modifications you must make to your Scout. Your steering, driveshafts, crossmembers, exhaust, body location relative to the frame, cooling setup, etc will all be different..........
There are a lot of good technical threads on this board and other boards that address all of what is or could be needed to accomplish this feat. This is a deep-pocket endeavor, unless you are an experienced fabricator.
If you absolutely must do this I recommend you find a t19/d20 combination from a Scout II. Make sure you get the v8 bellhousing, the flywheel and core clutch, and the correct throwout bearing sleeve. Chasing these essential parts backwards will be very frustrating, especially if you find out (the hard way) someone sold you the wrong part.