They were a breeze to install. You replace the factory bearings with a spindle, after putting the axles together, put the bearings in the hub, install it and the locking hub. I did the first one in about two hours. They're basically built the same as the old Dodge/Ford/Chevy. Of course there's dust shields and seals to install, but it's not hard at all, in my opinion. If you've installed twin turbo setups, you can do the hub kit. As far as the Dynatrac brand is cast instead of heat treated, only the outer hub is cast, the inner spindle is all high grade, heat treated, machined steel, same as a Dana 60 in millions of other applications. I don't think it will ever be a problem. I've got 40k on my '97, and I've not had any problems. If you go to dynatrac's website, they have installation instructions available online, I believe.