from what I understand the the 750GL was just a lower power version of the 750GX (and the lower power version of the 750FX was similarly called the 750FL) they are fully interchangeable and identical otherwise, they are the same hardware just binned for different applications
(I have seen 1Ghz PowerLogix 750GX CPU ZIF cards with 800Mhz 750GL's for example)
I actually have a few of both CPUs in the collection that I bought a few years back, I really need to unearth them and see whats what because I want to send a couple to
@max1zzz if he still has some 750FX based iBooks on the operating table, im really curious to see if a 750GX/GL can be swapped in (since the 750FX/750GX are pin compatible) although the BootROM of the iBook might need patching first (but thats not hard to do if it is needed)
another thing that would be cool would be if it would be possible to remake the PowerLogix 1Ghz G3 upgrades, they look deceptively simple
I had one for a short period of time that I was drop shipping for a fellow collector who very kindly let me play with it for a bit, and as far as I can tell they contain no active logic, its just ZIF PCB!
which I find really curious because they work in a PowerMac G3 BW without any Firmware patching and report back as a regular 750 to most software, so im really curious as to how PowerLogix did that with no special logic on their CPU card etc!
I also wanted to figure out what resistors set the PLL speed on those ZIFs since somewhat annoyingly PowerLogix had them set to 500Mhz in hardware which you then would raise to 1Ghz with their software (the 750FX/750GX having software controllable multipliers) but said software got broken by OS X 10.4.9 or there abouts, I personally dont really care about a low speed/power mode so it would be cool to have on that ran at full speed regardless of what inappropriate OS I am running on the machine its installed in
theres actually a whole bunch of 750GL's on ebay right now if anyone wants some to experiment with
https://www.ebay.com/itm/124258517963