new to trs and asking for help in the wrong thread

[mobile madness]

Am a member of to sites dedicated to rangers. I know this isn't where you ask question but... I have a 91 4.0 l v6 a4ld 4x4 stx. Lookin to crossover to a manual trans cuz my trans is goin out and its not even that old. Apparently a fm146 will bolt to my block and so will a m50d-r1. I can find the fm 146 but the m50d-r1 I've looked high and low with no luck. In my mind the thing is a mythical creature. Will I be ok if I use the fm146 is all I'm asking.