[JL8Jeff]

If whoever built the truck did actually title it in their name then they can just go to dmv and request a duplicate title. But if they bought the truck, built it up without ever putting the title in their name, then it would still be in the previous owner's name. The builder probably can't even get it titled unless they still have a notarized bill of sale. So I'm not sure you would be able to title it in your name without proof of buying it from the current owner. Also, you might want to check what the rules are regarding registration and inspection for an engine swap like that. I think NJ has some issue with a motor swap that has more cylinders than what the VIN says it should have. Definitely do some research before putting out any money on the truck.