The 65 66 Calipers were 3/8" Port to allow fluid to enter the Caliper.
The 67 Calipers were 7/16".
All the 65 66 67 Mustangs/Shelbys were K/H variety (Same Caliper as you see), 65 66 had the K/H clearly cast into the side, the 67 calipers were a bit different to ID as the K/H was on the end by the mounting hole for the Pad retainer.
After first 500 67's, Ford went to the 7/16" REDISIGNED 4 Piston Caliper with Side Bar.
All 65 66 67's will interchange (Regular Mustang to Shelby's) as long as you use the proper flex hose to affix to hardline.
These are BW Caliper Kansas City Kansas, Phone number 1 866 451 0195 Even Toll Free.
Quality FULL CAST Parts, Not the Argentina Light weight thin cast pasts.
Dan @
ChockoStang