GV Under/Overdrive in a AC?

[bobcowan]

8 forward gears is not that big of a deal. IMO, it's a bad deal. That's a lot of shifting. The main purpose of a seperate OD/UD unit is to be able to split the gears while shifting and keep the engine in a very narrow power band while hauling a heavy load. That's why they're such a heavy duty duty unit. You really don't need a 10,000# rating in a muscle car.

A lot of hot rodders liked to use them coupled with a C6 or TH400 because you could get an OD gear. That was back in the days before OD transmission became standard factory equipment.

Nowadays, an OD transmission is so much cheaper, lighter, and smaller that there's really no need for a separate unit. It doesn't make sense no matter how you look at it.

If I was looking for a new transmission, I'd look at the new heavy duty 6 speeds, with two OD gears.