1978 C6 automatice tranny questions

im getting ready to rebuild the tranny in my old ford for the first time and had some questions for any that have done this before. i haven't torn it apart yet, but if i wanted to go to the 5 clutch pack instead of the stock 3-4 what do i all need to change? Also i see where they have the extra-wide kevlar band......again, do i need to change anything to accomodate this change or will it work with the factory "internal hardware"?

The truck has a stock 400m engine with a mild cam. It's pretty much a daily driver/weekend play truck and it has 39.5 super swampers. For the C6 being so "bullet proof" i have gone through 3 in the last 9 years. I want to build it myself and beef it up to help with the large tires. any info on good websites or set-ups for my C6 would be greatly appreciated. thank you.