Difference between 930/911 Turbo and G50 rubber-centered clutch discs

[preston_brown]

What exactly is the difference between the G50 clutch disc:

950-116-012-04-M38

and the 930/911 Turbo clutch disc:

950-116-012-51-M38

They appear very close to identical, but I am sure some measurement is different. I'm especially curious because I know you can swap this spring-centered disc:

930-116-014-02-M38

with no other modifications.

Thanks for the insight.

[buttjoint]

I went with the turbo spring disc when I did my 89 because it wasn't rubber and going to take a poop.

[preston_brown]

Yeah, I understand the motivation. But that doesn't answer my question. What/is there a difference between the two listed parts?