Sounds like time to get wrenching, then. If you want it done by Turkey day you're going to have to hustle. You might want to have S&P send you a DVD of how to do the conversion. You may be able to do without it but it couldn't hurt. I have a friend that we put my old LT1 into his 90 C1500. I'll see if he wants to help you out with any other information. While waiting for the engine, you can swap fuel pumps and pull the old engine or are you driving it with the 383 in there right now?