Need An Upgrade Tranny SL6

I would like to up grade rebuild, my 66 Valiant 904 tranny . It has less than 100K on it. What would be a niece converter to buy for a daily street driver (hi efficiency fuel/power)? Whats difference of Trans go's TF 1 vs. TF 2 Kit?
I would like to install Kevlar bands, anyone ever put any in their ride? Would it be advantageous for me to add an extra steel in the clutch pack? Does anyone make a bolt in sprag or an upgrade product? Has anyone used Amsoil in their 904 trany ? Thanks for any input ,
Kruzz