Quote: The most power that a factory Merlin ever produced was 2,780 hp at 36 lbs boost in 1945 & even then it was a 'special' running on fuel with monomethyl aniline added. I doubt that Hadfields engine excedes this.
After the war the engine was redesigned & strengthened for freighter use [the 600 series] & these developed a lot less power but were run for far longer periods both in the air & between overhaul.
If he has one of the last engines, then he has one of these freighter engines.

I don't think that even the larger Datsun pickup models could so much as carry one of these monsters home, let alone accomodate one in the chassis.

[source, World Encyclopedia of Aero engines, by Bill Gunston]