boost feen

I'm looking at making some hybrid rear axle shafts for my Porsche as the outer hub flanges are of 968 variety but the inner gearbox stub axle flanges coming out of the G50 based 6 speed is of a special motorsports type and has what I believe is the 965 type that takes the larger later 928 part # cv joint with tin grease cap, larger bolts and flat washer arrangement. So I guess I need to know how many splines this cv joint is and how long of splines I need to figure out if they will fit on my stock axle shafts which I'm hoping they will? Also do they use the c clips to retain the cv on the axle with a keeper groove?

If they do work I'm hoping either there's a reasonable good used set out there for sale or cheaper than oem aftermarket supplier?
Here's a pic of my gearbox flange!

Thanks Shawn