Spare parts

There are a lot of places for engine parts depending on what you are building. You can get stock style parts from a number of places, like Rock Auto, NAPA, Advance Auto, and others. If you want performance parts those are available as well from places like Summit Racing and others. Body panels and interior parts are available as well as those trucks have a lot of aftermarket support. I would set down and plan out what you want the end result to be, then look at what you have as a starting point. Don't forget the supporting parts if you plan on a high performance build. IE you don't want to build a fire breathing engine and put it in front of a stock transmission. Or you might want to update it to a newer transmission and discover that means a custom driveshaft. You might even decide you want more torque and forego the 302 for a 360 or 400 instead. Really depends on the end goal.