Never been a T-56 fan.....big ole transmissions, heavy, long, and with the engines that guys put in Cobras, a .5 OD puts the cruising rpm in a spot where you get the "buck." In addition, a lot of different situations require modifications to the midplate on the T-56. This involves some machine work so that interference with the clutch fork doesn't occur. There has also been issues with the rear seals and I've had to send out some replacements.
That's what you have to worry about with overdrive transmissions. Most Cobra engines have thumpier cams than usual and they're usually not efficient until around 2000 rpm. If you try to lug the engine below that, you get a bucking sensation while you're cruising.
The TKO 600 is a great transmission and I sell a ton of them. The .82 OD's outsell the .64's because of the reasons I mentioned above.
Mike Forte could probably offer you a good deal, but that guy from B2 Motorsports can offer you a good one too.
