I have been running the TCI convertor and the Transgo kit for a couple of years now. You mentioned noticing a real difference in the truck with the convertor change. When you install the Transgo kit you will notice another worthwhile improvement.
I have known Bill Taylor, the founder of TCI, for years but never used any of their products before this convertor. A neighbor of mine was the shop foreman at TCI for years and recommended this convertor when my stock convertor developed a crack in the front hub weld. The crack was leaking and was too close to the thrust bearing for me to TIG weld it up. I immediately noticed a lot lower stall speed, even to the point of hurting off idle performance, a problem I cured with a simple injection pump adjustment.
The installation of the Transgo kit really made a lot of difference in shift quality. I am very happy with the results of the convertor change and kit installation.
Be sure that you get the TFOD kit. There is another kit, one sometimes referred to as the "Junior" kit, that you do not want. I recommend installing the kit in its complete form just as the instructions call for. I am going to be pulling my transmission soon to replace the front seal and will be checking line pressures before I do pull it and will be adjusting them while doing the other work.
Good Luck!!!