Hey Jeff, what do you like more on the EC cam over the cheetah?
Cheetah cams are like Crap-maros and Rust-angs -- too many people drive them. That's a big reason. But:
1. I have found solid increases in volumetric efficiency and dynamic compression ratio, even with stock compression and no head work.
2. 1-Piece billet construction over cast is good enough for me. I do not know the metallurgy of EC's camshaft, but simply look at the O.D. of the two. That tells you something.
3. Billet construction also allows for more aggressive spring pressures (If that's your thing) and higher RPM without breakage, with either the stock steel or stainless flavors. Exotic metal valves would be a breeze for this little bump-stick.
4. Lightweight camshaft drive sprocket means less rotating weight.
6. I like the idea of having an unmolested cam lobe, not cut down the middle and welded.
IF you insist on stock rocker arms, keep the cheetah. You will bust stock rockers with an EC cam EVERY time, even when using only the outer spring.
Given unmodified rocker pedestal height and 2 stock steel pushrods, you may have to machine an additional .05" off the top of the exhaust valve guide, but double check with a light "checker spring" installed so you can measure retainer-to-guide clearance.
Really, a billet camshaft opens up lots of opportunities to the savvy engine builder.