My reference is the Francis H Dean America's One Hundred Thousand.

North American's P-51D TAS SL is 365 mph Combat power. It is about 5mph less than USAAF tests.

My tests show that a Power_scalar=1.04 will attain that speed for the 3us_p_51d_25, 50 pct fuel, starting at 300 mph, 500 ft for 3 minutes.  The speed of the 51 is acceptable out of the box.

I thought roll stability to be a little unstable; my setting is roll_stability=1.1.

The 51 Merlin powered was a "less nice flying machine" than the original Allison powered 51.  The 51D low speed lateral controls were judged to be mushy but still good.

The 3us 51 is not a pure dogfighter like the Spit.  It can maintain relatively high IAS in dogfights with the AI 3us_190D-9.  Which makes the outcome much beyond reality.

The 47 broke the back of the Luftwaffle, the 51 will finish them off. CG 8th USAAF May 1944.