Stages arent an actual unit of measuring. One companies stage 1 cam is not exactly the same as anothers. Hell even one companies stage 1 cam isnt the same as another they may make, for instance skunk2 makes a "Tuner Stage 1" and a "Pro Stage 1" cam. The tuner stage 1 can be run on a stock valvetrain and potentially without a tune (though not reccomended) wheras the pro stage 1s must be tuned and you need higher compression then stock b16 or b18c1 pistons have to take full advantage of them.