[urq] differences in subframe bushings

[Brandon Rogers]

Ok so apparently, on 1984 Quattros at least, there at _3_ part numbers of
subframe bushings for the 8 spots.  And I'm just super curious what the heck
the differences are between them!!!?!?!?!?
 
The front two of the front SF get 857 199 415 B
The rear two of the front SF get 857 199 419 B
 
The front two of the rear SF get 857 199 419 C
The rear two of the rear SF get 857 199 415 B (same as front of front)
 
Anybody know the differences? durometer? diameter?
 
I'm also curious if these are the same P/N for the 4000 quattro - anybody
knows? (my FA is down....)
 
 
Brandon