P-51 Air racer.

Having read after the war the p-51 was snapped up and raced just like others what is done to a Air racing aircraft to make this faster & turn quicker?

The prop i guess is changed to a another pitch?

Lightened all armour plating removed and a nice tweek to engine but what is done overall to make this fighter a racer?

Found this makes a interesting read.http://www.456fis.org/P-51_AIR_RACERS.htm