Are you getting valve springs with that cam? I dont know what lift stock springs can handle but you would benefit from a matched set of springs. Also if you are comfortable changing the springs on the engine you could put on a lightweight spring that you can compress with your fingers and assemble and rotate the engine around near (before and after, it doesnt always contact only a TDC) TDC and push down the valve by hand to see how much clearance there is
It has performance springs. 115 pounds closed/284 pounds open. I wouldn't think of trying to use stock springs. Where are those checking springs sold?
I think comp sells some. I think I got some from an overhead valve head with rocker shafts, I imagine you may be able to find something at your local hardware store
The clearance should be checked when the valves are at overlap, between the exhaust stroke and intake stroke. Check every 5* from 15* BTDC to 15* ATDC. As mentioned above, even using the light weight springs will only give you the vertical clearance, not the radial clearance within the valve pocket. Also, whatever clearance you measure with light weight check springs I've found that when you put the actual springs in you get about .010" or .015" more clearance because the real springs do a better job of seating the valve and retainer locks. With the short cam you're looking to install I doubt you'll have a problem.
