350mph is wrong. Far too fast. The Model 32 had a different cowling, setup, and exhaust system than the later A6M5b, which gained significant speed performance with those changes. The -5b is 358mph or so. The Model 32 should be at least 15mph slower (if not more). Some sources online list it as 336mph, which is par with the A6M2 already in-game.
Effectively it was a new model, but from the pilot perspective it wasn't much faster, had less manuverability, and less range (with increased roll rate and slightly better dive speed).