[olddog]

Asking for opinions on the net for a measurement of clearance that needs to be measured is not a good way to go here. You can tally votes, take an average, or what ever statistics you want to use, but you should really just measure it.

Set a piston at top dead center. Take the intake and exhaust springs off on that cylinder. Carefully sit both valves down on top of the piston. Measure the valve stem height. Pull it all the way up and measure again. Subtract the difference. Repeat on the other valve. Then work with a cam manufacturer or builder.

Call Brent and let him verify what I told you or correct what I said, if I'm wrong (never trust the net completely). Then let him pick the lobes and special order the cam for you. I expect his guidance will be worth every penny he tacks onto what you could do for yourself.

Has your block been decked, the main bearings aligned bored, the heads milled, the pistons notched, who's rods, head gasket thickness, valves ground, seats replaced? All these things can impact the piston to valve clearance. Builders always check this even if they built a hundred engines like it cause there are so many variables.