I'll be the lone voice of dissension... <img src="/forums/images/graemlins/smile.gif" alt="" />

Keep the R150 and skip the 151. While the 151 is one of my personal favorite trannies, the expense, rarity and the modifications needed (shifter console) aren't really worth it to me anymore.

Do a quality rebuilt on the 150, if it's really more than the shifter seats (which I agree w/ Brian on, btw), with quality components, then throw an Inchworm or Marlin adapter and 4-cyl 23 spline 4.7 tcase behind it (just make sure you seal the splines in the tcase adapter coupler)... You'll be very happy and get another 175-200K miles out of it easy.