The Spitfire was an inter-war design that was capable of amazing development in a short period of time - from the 1030bhp early Merlin-engined Mk1 to the 2050bhp Griffon-engined Mk14 (there were other later marks that made the war such as the Mk21 but it wasn't a great plane initially and few were made). The Mk14 was still a handful according to contemporaneous accounts.[The Mustang]was the best escort fighter in the world, make no mistake about that. But this was because it had incredible range, but the laminar flow wing fitted to the Mustang could be a little tricky. It could not by any means out turn a Spitfire. No way. It had a good rate of roll, better than the Spitfire. So I would say the pluses to the Spitfire and the pluses of the Mustang just about equate the pluses and the minuses.
If I was in a dogfight, I'd prefer to be in a Spitfire. The problem was I wouldn't like to be in a dogfight near Berlin, because I could never get home to Britain in a Spitfire...”
From this:
to this
in about 8 years.
My favourite use of the Griffon engine is the deHavilland Hornet. Built like a Mosquito, powered by a pair of 2030bhp Griffons giving a 470mph top speed and packing 4 20mm cannons under the nose. Sadly it arrived too late for WW2 but would have been a boost to the long range escorting of bombers, as well as in the Pacific conflict where the Sea Hornet's long range would have been very beneficial.
No idea why I wrote Griffons. Got carried away, I guess. 
