I run a D&D Transmissions Viper-spec T-56 with a 670HP blown SBF, and 4.10 gears in a built Ford 8.8 rear end. I changed from the T-5 because I needed a stronger transmission.

In comparison to the T-5 the T-56 is heavier (as noted), longer (as noted), generally larger in circumference, and is noisier (lots of spinning gear sounds) and can be challenging to shift (esp. 2-3, a spring load shifter such as MGW highly-recommended).

And, with regard to your original premise that the T-56 will put the shifter in a better location, in my case (745 body) my shifter came up under the radio in a *worse* location than the T-5. So, instead of an easy-to-fab handle extension for the T-5, I had to fabricate an elaborate 6" extension to the transmission housing and internal shifter asseymbly. It all works great, but it was a lot of effort.

I do believe that the newer versions of the T-56 come with more options for shifter location (see the T-56 Magnum), and so that may be a better choice for you; this was not available when I installed mine.

And then there is the whole saga of the hydraulic clutch set-up, but that's another story altogether.

In the end, though, I have 4-5 great gears for drag racing, and I can cruise on the highway at around 2,000 RPM.

I wanted to post some pictures in image library so you could see for yourself, but the image library upload link does not appear to be working.