First question...does the '84 B2 have a hydraulic or mechanical clutch system? If it's mechanical, it will not work, even with switching to the newer bellhousing with the hydraulic slave cylinder, the input shaft is too short. If it's the hydraulic type, it'll work...for a little while. The 2.8 and 2.9 use the same 8" clutch but the 4.0 clutch is 10" diameter. Might as well use the one you have for now. The 24 year old trans that was behind the 2.8 wasn't the longest lasting trans even with the less powerful motor. It should last a little while as long as you drive conservatively and don't jump on it, and I probably wouldn't do much off road with it either. Start shopping for the right one before it breaks... when it does, get the clutch and flywheel from a 4.0 along with the new trans..
