I did one on a '46 ford panel and a '41 Hudson. Here's what I remember. First off, MEASURE! TWICE!!! Everything you can think of before you start cutting. Wheelbase, anything on the cab that might interfere, (shouldn't be to bad on a P/U). Next determine what you want for front stance (bumper height). Then measure the distance between the P/U frame rails and the floor at the front edge of the door. Now you can remove the front clip. Next mark the centerline across the frame where your current spindles are. Draw a square line across both frame rails behind where your graft is going to be, and measur forward to the spindle centerline, this will give you a reference to get the correct wheelbase. To prep the subframe, remove the subframe shocks and replace with a piece of threaded rod. Measure the distance between the a frame stoppers and the stops. Tighten the threaded rod until that distance is cut in half (this simulates engine weight). Mark a center line across the spindles as you did above. Put the size tire and wheel that you plan on using on the subframe. Next level the trailing "legs" of the subframe. Now set your truck on stands at the height you determined above. I like to roll the subframe along side the vehicle to help with perspective. Using a square on the floor, find that magic place where the height of both frames will intersect while maintaining the correct wheelbase. MEASURE AGAIN!!! You only get one chance to cut! I like using a sawzall, it makes a cleaner cut. After you have 4 clean cuts, I suggest welding a "butt" plate to either the truck or the subframe. Roll the two together, weld the butt plate to the corresponding rail, and then gusset and box the assembly together. It sounds like a daunting process, but the P/S and disc brakes are well worth it. You can graft the front section of the original frame to the front of the sub to provide you with front clip and core support. Hope this helps!