Nothing against anything here, I just don't like a one trick pony. My T56 is an 833 1st-4th gear and then its 168mph in 5th at 6000 rpm and 2000rpm at 80 mph in 6th. Any transmission that can be bolted to a 318 can be bolted to a GenIII.
This is one of the main reasons I ended up with a T56. I made a spreadsheet with all the main transmissions options and looked at gear ratios and rpm drops between gears and the 833 was my favorite. The T56 is nearly identical with 2 extra gears as stated. Most of the aftermarket setups (namely TKOs) have super granny first gears and huge rpm drops from first to second which I really didn't care for.
As far as brands, the primary differences between them are the input and output shafts. Ford, GM, and Dodge (Viper) will have different tooth counts for both shafts I believe. The earlier Viper ones also use a standard 833/727 driveshaft yoke I believe, so you can reuse it, which is one of the main reasons I wanted a Viper one since I just bought a new yoke earlier. Later Viper ones use a bigger yoke. The gear ratios are pretty similar between all the brands too. The main difference is in the overdrive gears. All Vipers versions and a few others use a 0.5:1 final overdrive and I think 0.74:1 5 gear. The other option is something like a 0.64:1 6th gear with something like 0.8:1 5th gear.
