84 cars started the 12 hour in 1983.

I heard they were thinking of adding a GT3 class to get more participants in ALMS but the speed differential would be too great from GT3 to P1 and it would be dangerous.

They probably should adopt some budget constraints like F1 tossed around before being stupid about it; make the manufacturer teams play fairly and then see what the teams can come up with using their ingenuity and drivers instead of check books. It's easy to get an edge when you can get the latest Michellin tire technology that the other teams don't have because you have a big name team.