Not to come across as argumentative, but while both of those modifications will change the way the vehicle performs, neither will affect the relatively larger gap between 1st and 2nd (larger, that is, than a TH350 or TH400). Changing either is external to the transmission, so the gap remains unchanged. Changing the planetary gear for a different unit that is geared with a different ratio from the original is the only way to change the difference in ratios between 1st and 2nd. One of the differences that exists between the 4- and 5-pinion planetaries is that the 5-pinion units (at least some of them) have reduced the 1st gear ratio from 3.06:1 to approx. 2.84 (couldn't find the exact specs as I'm writing this). That is the only way to change the 1st - 2nd gear gap.