'Race' as in 1/4 mile racing? Standard heat range, stock or aftermarket heads, NGK 5 heat range.
Race, as circle track racing at WOT, a colder plug should be used. Power adder, nitrous, blower etc also needs a colder plug.
The tip location is the same for THAT plug design. What changes with heat range is the amount of insulator area that contacts the spark plug body to transfer heat away from the centre electrode to the body..
AAAHHHH....the old NGK plugs are "best" ...controversy lives on and on an on.....ad infinitum....if a person thinks NGKs are best....great....I use what the engine likes, albeit CHAMPION, AUTOLITE, AC etc that does not make my brand selection the best....only my preference.... just my opinion of course....