Quote Originally Posted by Twizted 1 View Post
From what I've encountered in a 4t65e there's no way that only one chain can run at a time. Both chains drive the gears together. One chain doesn't disengage while the other engages.
They are both engaged at all times.

But the 7/8 and 1"chain are quite a bit stronger than the stock dual chains.
The gears are offset. So, only one chain is being pulled on at a time....well, not completely, but that's kind of how it works.