Im about to do a 411 pcm swap on my 98 silverado. The guy I bought my EFILive from sent me a stock tune for a express van and a modded tune to get me started. The question I have is do I have to load the stock tune first then the modded tune or can I load the modded tune first?

I also have another question. What do I have to do when I hook up to the new pcm for the first time because it has a different vin number stored in it. I think what im really asking is do I put my truck vin when EFILive ask for the vin or the one that is stored on the pcm? Sorry if this is confusing, cause im really confused right now. Havent tried it yet but dont want to screw it up.