I think you'd hafta talk to the cam makers for credentials, there's still some that use the 3/4 designation at least

as an old flathead junky, I'd say the terms started in the flat motors' heyday, before the duration/lift specs started getting as exact as they are today and cam grinding was more the DIY edge "weekend racers" used .... a somewhat 'lumpy' grind was 1/2 or 3/4 race, a real radical grind that was hard to keep running at less than full throttle was full race

now 'full race' would prolly be mechanical rollers and a real radical grind, but I think largely the use of those terms nowadays is meaningless

Bill

Moved over to the Passing Lane

"When we tug a single thing in nature, we find it attached to the rest of the world" ~ John Muir
"When we tug a single thing on an old truck, we find it falls off" ~ me
Some TF series details & TF heater pics