1965 CA Law
Hi Zomby, I am aware of this law, tho many others might not be. Prior to that law, EVERY time that a car or motorcycle had an engine swap (wore-out, blew-up, whatever), the owner had to go down, have the vehicle inspected, and the registration updated to show the new engine number.
Your registration showed the engine number, and cop could check ANY CA vehicle for correct engine. A lot of Harley Riders got hassled on this one (tho some of those bikes were hot in those days).
As the bodies and frames last almost forever out here, and some of the engines were CACA (remember the Corvair?) there were many legitamate engine swaps, and CA DMV eventually got tired of, or forced into accepting, that they would no-longer be the "keepers of the engine numbers' for the growing population of CA.
Sorry to stick a match to your Zepplin, BUT this does NOT mean that you can even psudo-legally take an under 2hp class vehicle and put 11+HP in it! Not even in a fun dream would that be even close to legal, and the old1965 engine swap law is true today, when I pulled the 235 6cyl out of my 64 chevy panel, and put a 1978 305 v-8 that was legal, and required no paperwork, same with the Model A when I put the 327 in it.
Mike