The Wilwood 120-11136 is a forged aluminum, four-piston, lug-mount caliper from Wilwood's Forged Superlite Internal (FSLI) line. Its piston count is 4 with a total piston area of 4.80 in², and the pistons are stainless steel. The manufacturer says FSLI calipers are a direct replacement for Wilwood Superlite and similar competitor calipers with 3.50" centered mounting tabs, so this is a practical upgrade for a 1.25" rotor setup. Compared with a stock caliper or a generic budget unit, the stainless pistons and the forged body are the main reasons to pay for this model. At 5.2 lbs per the manufacturer, it is also lighter than many older race calipers. Owners on user forums commonly report that a race-spec caliper with a 1.25" rotor gives firmer pedal feel under repeated hard stops.
Before buying, confirm your rotor and hub geometry. Wilwood lists a maximum rotor diameter of 13.06 inches, a minimum of 11.75 inches, and a rotor width range of 1.19 to 1.38 inches. The caliper uses the same bridge-bolt pad style as Wilwood's Superlite 6-piston calipers, which the manufacturer identifies as a 7420 type bridge bolt brake pad. For installation, Wilwood's Superlite assembly sheets call for shimming the bracket so the rotor sits centered in the caliper, then torquing the caliper lock nuts to 30 ft-lb after pad height is set. Owners on user forums warn that off-center mounting is common on some setups, which can leave the outboard pad binding, so check centering before final torque.
The manufacturer states that FSLI calipers are a direct replacement for Wilwood Superlite and similar competitor calipers that use 3.50" centered mounting tabs. Confirm your bracket's mounting-hole spacing before ordering.
The manufacturer specifies a 7420 type bridge bolt brake pad, the same pad used in Wilwood's Superlite 6-piston calipers.
According to the manufacturer, the caliper is designed for 1.25" rotors and lists a compatible rotor width range of 1.19" to 1.38", with a maximum rotor diameter of 13.06".
Installation is an intermediate job that suits someone comfortable with brake bleeding and suspension alignment. Wilwood's assembly sheets for its Superlite kits have you install the bracket with clean, dry threads and shims, check that the rotor sits in the center of the caliper, and apply red Loctite 271 to the bracket bolts once alignment is right. The sheets also recommend removing the bridge bolt to seat the pads, checking that the pad top is flush with the rotor outside diameter, and bleeding the farthest caliper from the master cylinder first. For fluid, Wilwood's sheets recommend Hi-Temp 570 or EXP 600 Plus. Tools you will need include a torque wrench, a shim set, and a bleed kit. Confirm each torque value against the sheet that matches your specific kit before you assemble.
