Hello -
I had everything apart and accessible last week and took some measurements. The cliff notes version is that the 2 CVs ('74 CV w/(4) 10mm bolts and (2) pins and a late Carrera G50 CV w/(6) 10mm bolts) are almost identical. I have replaced the inner CVs on my '74 axle w/the later G50 CVs and while not yet installed in my car, it looks like it should fit.
Some things to note:
1. I'm sick of CV joints. I was going to type out a long summary of the work I did, the options I had and why I chose to do what I did, but I am burnt out! Maybe someday I will add more explanation - if you have any specific questions please ask.
2. Please take my measuring w/a grain of salt - ie: I'm not perfect.
3. The end cap on the G50 CV will NOT fit inside my '74 transmission output flanges. Note the difference in recesses in the pics below.
4. Note that I did have to mill the end of the G50 flanges to fit in the 915 diff.
5. I did have to modify the '74 end caps that the rubber boots fit onto to accept the additional 2 10mm bolts of the G50 CVs. This required drilling holes and some hammer work to create recesses for the moon plates to sit flush.
Here's some measurements and photos:
