If you have an original frame and you cut out the original frame number and switch it to another frame, you are not altering the frame number. You are altering the frame just as you are altering the frame if you change the front cross member, ****** mount or the rear end. You would have to be a piss poor fabricator for your frame alteration to be noticed. You could easily make your spliced cut 12" on either side of the frame number and after the welding cleanup, a needle gun would blend in any difference. I've had the DMV check frame/ serial numbers, and they just wipe off the number with a rag and check it against the ***le. I'm sure they know how the numbers look for that year of car/truck. Some people have been watching too much tv. But then again, I may have missed the helicopter hovering overhead and the good-looking babes in their form fitting pants and blouses with their million-dollar x ray machine ready to verify the authenticity of the serial number. I probably missed the Hummer with the NCIS emblem on the side. Jay Leno had a 32 Ford built with an aftermarket frame and he pointed out how they cut out the original serial number and welded it onto the new frame. They didn't blend in the welds and made it so it was obvious what they did. He pointed this out in his video and the California DMV had no problem with it, he said. He's not in jail yet that I know of.