I wonder how much it'd weigh extra to put in the stronger gears, hooks, strengthened lower rear fuselage, folding wings and so on. Especially when you consider much of the extra weight which came onto the P-40 was armor, bullet-proof glass, self-sealing fuel-tanks, extra guns, provision for an extra 1500 pounds of bombs. The aircraft was pretty much built like a tank otherwise.
What I'd be conserned about is whether the P-40 would meet over the nose visibility requirements which is very important for carrier ops. However, the F4U had a pretty long nose and it did okay