Hy WP53, welcome, this question probably belongs in the High Performance forum. The V8 engine swap in that style of truck is not an easy one, because of the stock steering box location a V8 will not mount without doing something about relocating/replacing the stock steering column/box, a front clip being the most drastic way of accomplishing this task. There is also the rear axle to deal with as the stock one uses a torque tube style rear axle which will not be compatible with modern transmissions. Ask yourself if you really need the V8, or would a larger 6 cylinder do the trick. A 261 engine is the largest that can be made to bolt in, or you could install a more modern 250 or 292 which will allow the newest automatics to be installed, there are many ways and opinions on "hot rodding" these old trucks and I'm sure more ideas will be coming along, hope that helps.
