Yes. Just to use Peterbilt as an example depending on the vintage the cab doesn’t even need to be from the same year. In a case with a ‘65 351 that we built here recently we used a ‘69 aluminum cab with the ‘65 build plate and number. The ‘65 had a steel cab with a bit of rot. ‘54-72’s were basically kept the same with a few changes. The ‘73-‘87 Petes used the same cab. Many have been replaced with different years for rebuilds with no issues. Same with the 379’s run of almost 20 years. Numbers stamped on used replacement parts mean nothing if they came from a clean donor vehicle. This same thing is done in the collector car world. “Clones” are built from parts of lesser cars to replace the rotted or wrecked originals. Perfectly legal.
Here in Tejas I know of a few cars and trucks that have been totaled out by insurance companies and bought back by the owners me included. The titles stayed the same. They were not changed to a salvage title. That generally only happens if the insurance company keeps it and sells it to a salvage or used dealer via auction. Also I have bought many complete parts cars and trucks from junk yards and the titles were still just regular issued titles because it was considered a normal private sale and insurance companies were not involved in the junk yards original purchase of vehicle.
……..so will a 3406C. Kinda funny when you hear the stacks start to vacuum whilst smoke comes out of air breather…….horrible oil pressure lol!
The EPA inspector would probably be young enough to not know what he's looking at. He'd be so confused by what he saw he'd just forget about it and send you on your way