The 1/2 ton Warn hub is the M-8, the early versions have M-8 stamped on the brass disk in the middle. The later ones do not. It is an internal mount hub, unlike the 3/4 ton ones that are secured by bolts to the outside of a hub (just like the ones on old jeeps and Scouts. The M-8, being an internal mount hub is secured inside the hub with a spiral snap ring. The modern 67-80? hubs will not fit, they can be made to fit, but it requires turning off about 3/4" of the outside of the hub and cutting a internal groove to secure the new hub and cutting a seat for the hub itself to go into, AND you have to get the right spline count for the axle shafts. I looked forever on the net to find one, I got lucky. I emailed Jim Carter and he told me a guy in Pryor, OK had some, I got mine from a Internet wrecking yard for 50$
