I talked to Pyro on Thursday for about thirty minutes and one of the many things we talked about was the Spitfire Mk V changes. It will be a Merlin 45 at +12lbs boost with two Hispano Mk I cannons (60rpg) and four .303s Spitfire Mk Vb. I specifically confirmed that.
We also talked about some other things such as B-29s, flying boats, Mosquitos, Me410s and the Spitfire Mk VIII.