Truck Identification

[GMC_Aaron]

I recently purchased a GMC Super Custom truck and was wondering how I could I.D. what features it had from the factory. I have problem though. I know you're supposed to be able to do it through the number that is tagged in the glove box, but my truck doesn't have it. It was restored and the glove box was taken out, which had the model number tag on it. My question is, how do I do it now? Can I do it through the vehicle I.D. number somehow? This is really bugging me,because it is real important to me. Any help would be greatly appreciated.