[ls1nova71]

The vast majority of mis-match parts problems you hear about are for the Drive By Wire applications. If you are going DBW, then your throttle body, TAC module, gas pedal and PCM need to match. There are several years of each that can be mixed, but if you don't know exactly what you are looking at, just taking a sellers word or the year written on the truck at the Pick N Pull can be problematic. As a general rule, on the truck engines, 2000-2002 DBW parts are the same, 2003-2005 parts will interchange and 2006-2007 Classic body style parts will also interchange. Now there are some parts that will interchange between more years, but this is where it gets complicated. See what I'm getting at? This is what people are talking about. If you are going DBC, then it's much easier because 99-02 trucks are easy to find and all parts will interchange. If all you have is a long block, I would try to find a complete pull out, since buying all the pieces will likely cost you more in the long run if this is your first rodeo. I've pieced them together on the cheap, but I've been doing this for 15 years, and have a pretty sizeable stash of junk lying around. LOL.