Searching has lead to a bunch of different opinions, so I thought I would throw this out there and see what these are all together. I plan on putting an SM420 in my 71 FJ40. I like the 3 spd, but as my skill has increased, my desire for lower gearing finally reared its head. I use this truck mostly for trail driving, but sometimes running around town on the weekend and the occasional drive to work, which includes some highway time. I do not trailer this truck, nor do I plan to. I will be putting on 35's on a 4+" SUA lift. Question: With my intended use of the truck, if it is similar to your experiences, how would you compare the 3 spd with the SM420? Pluses? Minuses? Regrets?