When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Thanks for the photo Oddjob; I am trying to see how they differ from the street car brake shields. I had a note that the cup car (ending in .30) shields are [made] from the street car parts (ending in .03).
Though, I don't see anything glaring, maybe larger "cut outs"? Here are the street car shields (parts ending in .03).
The upper pic I posted is very possibly a current production part, as that is from a restored Euro Cup. The lower pics are original, but not of an angle to show much.
I think its probably unlikely that the cup parts were made from the 03 part, because that is a later production superseded part. The 00 part was on the street cars at the time of the cup production. Street cars didn't have the lower brake cooling scoop until the 968, where the cups had a lower scoop starting in 87 (so that was the first need/use for the lower cutout on the backing plate).
There is a note in PET stating that the 00 plates needed to be modified for M030/M758 use. Potentially the backside cutout for the caliper was not large enough for the 928S4 calipers (?).
The notes I was looking at about the cup shields ("30") were actually from 1995 for application to a later Motorsports project. Maybe if you needed a set of cup shields it was easier to use the "03" shields.
Your note on the trimming for the caliper makes the most sense; Since the 03 parts are cut for the ducts, If you start with those then it is one less operation to do in order to have yourself a set of "30" shields.
This pic is the motorsport dust shield from and leaning on my -89 Turbo Cup. Can't say I can see much difference from the later production part. Can get better pics if needed.
The Turbo Cup control arm brake duct however is alot different and quite a lot bigger than the later 968 version.