Pistons are around 1 5/8. Looks like they were running a 1 1/4 rotor. 5 1/4 center to center bolt holes.
IF YOU'RE LOOKING FOR GOOD USED RACE PARTS SAVE ME IN YOU SELLERS AND CHECK OUT MY OTHER AUCTIONS! The item "Wilwood brake calipers 5 1/4 ump imca dirt late model wilwood winters howe afc" is in sale since Thursday, April 18, 2019. This item is in the category "eBay Motors\Parts & Accessories\Performance & Racing Parts\Auto Performance Parts\Chassis, Suspension & Brakes\Other".
The seller is "njc_raceparts" and is located in Northville, Michigan. This item can be shipped to United States.