No prop plane flies at 475 at 1-5k alt. Even 400 is something WWII planes were barely capable of in this range.
that's a pretty broad statement! it could be construed wrongly, maybe you should have said WW2 planes only!
I give you the F8F rare bear
http://www.rarebear.com/rarebear/records/While I do not know the required alt at the race track during the races,( i bet it ain't very high)
and she is a long stretch from the post WW2 plane she started out as,, she is still radial engined and propeller driven!
yet 495mph only got her a second place at Reno in 2003!
Rare Bear has also set many performance records for piston-driven aircraft, including the 3 km World Speed Record of 528.33 mph (850.26 km/h) set August 21 1989, and a new time-to-climb record (3,000 meters in 91.9 seconds set in 1972 (9842.4 ft - 6,426 fpm), breaking a 1946 record set in a stock Bearcat).