Made from 4130 heat treated forgings, 2.00" long, for 85mm (3.347") O.D. bearings with 45mm bore with provision for seal (p/n 58509). Drilled for 3" square symmetrical bolt pattern and requires 3/8" diameter stud kit (p/n 58570) to retain caliper brackets.  Commonly called Lamb type pattern.

Why are Mark Williams housing ends different than all of our competitors? First, we start with a heat treated 4130 forging not mild steel  material. Most builders use 4130 tubing for the housing. Why put mild steel on the ends?
 Our ends are slightly longer than the other on the market, allowing for an inboard seal in case you have a leaky wheel bearing. Being further out the  weld distortion doesn’t have an effect on the diameter for the bearing.  Also, our ends are bored with a very slight taper that allows the housing end to distort slightly, but not get tight on the bearing. There’s really no comparison to ours and all the questionable quality parts on the market.