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.

If I do this my converter will be an ATI and I will be sending an ATI core to them and tell them my specs to have one built.

Did you know that Jerry Meny runs a pg? He had some issues with starter rings comming apart, almost sawed the frame into.

Do you know what kit or adapter that Jerry was using?
One thing that I am taking into consideration is using the Coan adapter kit and using an actual Powerglide without a Bell. This for the simple fact that there are always spare glides laying around in my buddies shops and trailers for that matter.

JW bell here, in a big block A body though. Stock case with Bruno's shield on the trans, fits tighter spots than most shields, and bolts to the pan not a sheet metal strap under the pan. I cut the glide bell housing off in my garage with a sawsall and a die grinder. No issues here with the JW bell. There are a lot of choices for a glide. Stay away from helical aftermarket gear sets, the stock 1.76 is the budget way to go, if you ever upgrade don't consider anything but a straight cut set.

I don't think you will have any problems. I first adapted my PG with a TCI adapter plate. Used it for years but when I took it apart the flexplate was broken between each mounting bolt. It came apart when I took it off. I then bought a bell and cut the PG bellhousing off and bought a wheel. Worked excellent, no problem that I can recall. My next step was to go with a complete JW cased trans. Bought it with a wheel and a SFI deep pan. No blanket or flexshield required. I subquently bought one of the JW rollerized tailhousings. Again, I've had no problem, had to space out the starter but JW provides shims for that. All this went into a 68 Barracuda, I wouldn't go any other way. However if starting over at this time I would look at some of the other SFI cases out there.

Any more info? This has been a great thread for learning.

Jerry phone # 812-319-6878

Thanks.