OK! Finally I can breathe again.....!!!
Great info you've dug up here on the clips and calipers. I knew the 12/3 (rear style) were used on a few cars (like mine!) but not too common. I'd heard about the 17/3's up front and on the Group5 Panteras(???) but never run across them on the Goose but for rumors & whispers....
If all the cars around 1076 and up got the 3 piston cast iron behemoths....that's about a quarter of the production run which is significant!
I confirmed that the SP2524 seal kit is the same as I found for the 12/3 rear calipers.
What did you find for the seal kit for the 17/3 fronts???? (I didn't see anything in the XLS doc that I could decipher...but hard to tell from the list unless you know the caliper assembly part number....and the magic decoder ring is missing.....!) All I could tell, is that the 12/3's were used up front on the 3500 GT's?
Amazing that those small 12/3 pistons are so easy to find now..... I had to order them from the UK and a club member hauled them back here in '96-97 or so!
Cheers!