Based on most of the things I see, a Glide is over twice as efficient (less power to operate) than a standard, non-roller 727. And only slightly more efficient than a 904. But it's also lighter. That equates to power reaching the tires and MPH.

The big factor is the low gear ratio. The importance of finding that sweet spot of "not too much, not too little" is overlooked by many people. Whether it will help and by how much depends on your situation.

Typically though, going from a 727 to a 904 with basically the same low gear, which I have done, is worth a tenth or tenth and a half. Going from a 904 to a Glide, it didn't really pick up much. But the consistency and how the car worked in the first 60' was way better, AFTER we got the right low gear in it. It was a turd with the 1.76