Kevin
Your reply to D type should have stated "80% of AMERICAN land speed racers".
The way in which National race organisers break down vehicle types is up to them - and only the USA & Australia have currently got classes for various body types under the SCTA rules. But nowhere does the FIA prevent a speed record racer from attacking an International class record.
If you are fast enough the FIA will sanction a speed record attempt by any type of safe vehicle at any location in the world. As JackD points out even USA built SUVs/trucks have held (or do hold) FIA speed records.
The argument will continue as to whether a 'World Land Speed Record' should only be acknowledged as such if it has been be set by any racer, in any safe vehicle, to a standard set of operating rules, at any track location, in any country of the world.
Of the differences between SCTA/BNI and FIA I feel it remains the operating rules that have become the greater stumbling block - two way runs, over the same mile piece of land, completed in 60 minutes, with no assistance - is how racers have striven (& some perished) to be acknowledged as the best in the World.