What makes a stage 1?
What makes a stage 2?
What makes a stage 3?

 

Stage 1 is A/C, pipes, and re-jet (carb) or tuner (EFI)

Stage 2 is Cams added to stage 1

Stage 3 is Headwork added to stage 2

Stage 4 is????

Where does Big Bore fit in though?

 

Another way of thinking of the various 'stages' is that each one involves deeper surgery of the engine. So adding to 09StreetGlider's comments, a bolt-on big-bore kit could be regarded as Stage 3, but machining the crancase mouth to take a yet bigger bore might be Stage 4.

 

Thanks guys!! Then I can't wait until I get my stage 2 next month from Jamie @ Fuelmoto!!

 

I usually think of the Stage II being mild cams, big-bore, and mild compression increase. With my cam-only upgrade to the TC96 I facetiously call it a "Stage 1½". This is how HD defines the various stages, based on the equipment included in their kits:

Stage I: AC, pipes, tuner, plus optional displacement increase (103").

Stage II: Stage I plus displacement increase (103"), compression increase (10:1), and SE255 cams.

Stage III: Stage II plus 10.5:1 pistons, SE 259E cams, and hi-perf valve springs.

Stage IV: Stage III plus SE 260 cams, SE 110+ heads, 58mm throttle body, and Perfect-Fit pushrods.

The Stage IV is "not compatible with cruise control," they say. I wonder why not? Maybe they are trying to discourage this option. Back in the '60's some car manufacturers sold race-ready options like Chevy's L88, which was a 427ci Corvette race engine that needed to be offered to the public to qualify for some racing classes. You could order it, but to discourage it Chevrolet lowered the advertised HP rating to 430 (actually >500), five less than the standard tri-power arrangement for 1967, for example. You also couldn't order it with a radio or heater, which nixed it as an option for most buyers and also makes these very scarce and worth a fortune as collector cars. Anyway, I digress.