[rdorman]

You will have to check. And you can do this with the heads on. Get some of those wimpy valve clearence checking springs and put them on. Set up a dial indicator and measure clearence both sides of TDC for a ways on both strokes. From there you will know how much clearence you have now and how much more lift you can tolerate. Seems to me you want to stay above .08 on the intake and .1 on the exhaust.
Rick