My list of mods.
FM2 with 2x 20mm Hispanos.
P38J with 2x 20mm Hispanos in the nose, and 2 .50 cals next to the cockpit on both sides.
P47M with 6 20mm Hispanos and 2 .50 cals in the nose.
Ki-84 with 4 cannons instead of 2 .50's and 2 20mm's.
A6M (32) with more armor and a better engine.
190A8 with 4x 30mm's in the wings and 2x 20mm's in the nose.
Typhoon with an even bigger engine and two .50's in the nose, along with the 20mm's replaced by 30mm's.
P51D with more rigid wing structure, bigger engine and more aerodynamic frame and the ability to carry 4x 1000 pound bombs, 10 rockets and a center racked 500 pound bomb, or 2x 1000 pound bombs, 16 rockets and a center racked 500 pound bomb. Basically a flying ball of destruction.