Here is a used pair of WILWOOD aluminum 4 piston brake calipers. They have the 1.75 pistons and the 3 1/2 bolt spacing.
Takes the 1.250 brake rotor. This item is in the category "eBay Motors\Parts & Accessories\Car & Truck Parts & Accessories\Brakes & Brake Parts\Calipers & Brackets". The seller is "wilsonmotorsports2012" and is located in this country: US.
This item can be shipped worldwide.