[427mudflap]

The 1965 & 66 calipers use a .375 X 24 hose fitting, the 1967 use a 7/16 X 24 brake hose fitting. I had Wilwood 4 piston ( 1.75 dia. ) pistons on the front of my 1965 mustang and could never get it to lock the front wheels, changed to the stock cast iron factory calipers and they work great, don't use the aftermarket stuff unless you have to, alot of it is junk. Cast iron has 3 times the flex strength of cast aluminum. They only weigh a little more than the wilwoods.