I would like to swap my current cam for something more aggressive. My current setup consists of a zz4 short block, trick flow heads (old style) and a HR-276-2s-12 cam, .488 .509, 214 and 222 duration. Spoke with comp cams today and was told that a cam with more lift or duration might cause clearence problems, ie.. valve to piston contact. Anyone running a zz4 with a larger cam? Opinions welcome....

 

If you stay below .575-ish, you probably won't have V-P clearance issues. Besides, it's not really the max lift thats all that important when it comes to VP clearance. Valve timing has a far greater role and the only way to know for sure whether or not you will or will not have issues is to dummy it up and test it out.

I used a set of soft springs and a dial indicator.