I'm sorry. I read a post asking about the reason for choosing the .38 Super over the 9x19, so I hit "Simply Reply" and replied. If I did something grievously wrong, please let me know.
Maybe I should answer ever post like so many other posts I read:
"WST"
or
"Dillon"
If we are now ONLY talking about G34 conversion to .38 super, it would all depend on the frame and magazine opening. A 10mm Auto or .45 Auto frame and a 9mm slide would be the place to start a conversion. The .38 Super is enough longer than a 9x19 that is unlikely that a stock 9x19 frame or magazine, scaled to 9x19, will be able to work.
As much as I love the .38 Super, it just makes more sense to buy a gun that is already chambered in .38 Super than to spend a fortune to convert one.
Besides, there are other excellent guns other than Glock.