if you have the 88 r150f book it,s all you need. they are the same except for a different ratio 1st gear. that also means the counter gear is diffrent for first gear too. I've got a r151f,r150f and a r150 apart to make 1 transmission work. the only other thing i can think of thats diffrent is the rear shift lever shaft  in the transfer adapter. one word of warning. the gears on these transmissions are very easy to chip if you use something hard to pull or press them on. did you get the r151f t case and adapter?