No! I believe the gear on the end of the input shaft is part of first gear. Since the H41 and H42 have different first gear ratios, they do not cross over.
The H41 is a non-USA/Canada tranny and unless you or the PO bought the tranny from someone like SOR you can be sure you have an H42.
One is longer than the other and the spline count is different. Trust me, I wouldn't have gone through the trouble to swap input shafts with the FJ55 when I installed a 3B if I didn't have to! It's NOT an easy job.
Yes, but the question is "Can a "B" series H41 or H42 fit behind a 2F?" and the answer is yes ONLY if the input shaft is swapped out. "F" series and "H" series engines use the same input shaft and the "B" series engines uses a different one.
YES!! If it had the single piece case originally. ie. it's a 16 spline output shaft. The FJ55 and the FJ45LV both have the 3 speed transfer case on a "B" series 4 speed.