I suspect that no version of the P-51H will beat a Bearcat to 10K from a standing start. The F8F airfoil was a fat high CL to alpha airfoil, it had a lower wing loading, had enough Thrust HP to keep pulling through 10k - so a.) take off roll is less, b.) it climbs at a higher AoA and c.) it won't run out of Thrust (relative) before 10K.