Auto body repair & detailing: vin #s?, salvage title, salvage vehicles

Question
I have a reg cab truck and a crashed up extended cab truck,I want to swap the extended cab on to the reg cab and weld it on,and switch frames and whatever else.My question is what VIN # would i use the reg cab's or the extended cabs vin?Or can i just change ownership over to extended.Is there a way to get a new vin #?

Answer
I don't know the laws in your individual state, and there are 50 different states, with 50 different sets of laws. You will probably have to apply for a salvage title, or a self assembled title. Keep all receipts for parts, fully document all work, and be darn sure you have titles to both vehicles. Check with your individual state laws concerning vehicle titles and salvage  vehicles. What you are proposing work wise is just about the hardest thing you can do, and do right. This is a difficult task for a seasoned professional. You sure you want to try this? I would check into the salvage laws, and once i was sure what had to be done legally, I would purchase a used cab. Nuts and bolts are easy, welding, grafting, and fitting 2 very different cabs together- that's a whole different ball game. Bill