[dsraven]

check the inside diameter of the wheels against the assembled diameter of the disc and caliper assy. usually the issue with the old wheels is they are contoured differently on the back side so there is less room inside the wheel for the caliper and they end up rubbing the back side of the wheel or the wheel simply doesn't fit over the caliper to begin with. a newer wheel may fit and allow the same tire size. a toyota wheel may be the answer. if buying some wrecker parts you might ask about the wheels being included in the sale for a better deal if your old wheels don't fit over the toyota calipers. maybe even take an old wheel with you and check the fit at the wrecker before the parts are removed, then you know for sure. grab the brake master cylinder as well as the proportioning valve so the disc conversion uses all the balanced parts from the same vehicle. you would likely need to make the master cylinder fit your truck though. a lot of guys add power brakes at the same time. that can be a challenge if keeping the master cylinder under the floor because the booster needs to be smaller diameter. some guys will adapt a hydroboost down there instead or mount the booster on the firewall but then you need to modify the pedals etc, and put up with the booster under the hood.