Nothing wrong with using stock glide cases, even stock 1.76 gear sets. You wont have any strength issue's.
A few parts in those tranny's are need to be replaced, but after this you will have a strong transmission.
I have personally put pass after pass on a stock glide with stock 1.76 gears. Built by yours truely, turning 1.07 60ft times
A few things that need changed.
-300M input shaft
-aftermarket clutch hubs that holds more clutches
-billet servo piston-Kevlar bands
-1.76 planets
-aftermarket valve body
-deep pan
-pump mods
-case mods

If your not chasing E/T in a class, lots of people don't care to give up a little E/T for consistency.
E/T loss could be substantial, maybe a tenth or more. Then again it might not be near that much with the right converter.
I want to add that converter choice is a little more crucial in a glide, so ask around and get some recommendations.