As a min.? I can’t remember having an issue and the only guide I’ve have followed was the MP engines book which to be honest gives measurements and clearances to a slightly generous size because many people out there will push the limits of what they suggest and screw up there engine. So the MP books suggest a “SAFE” clearance measurement.
Follow that and you’ll not have a problem.
The closest I have ever run a clearance I didn’t measure and dang well should have! I installed a Comp solid 296S w/a .525 lift, then the proper lash was done (which was generous because the engine was cold) and found that the intake valve, while not hitting the piston was so close it did not allow the black carbon to left behind on the piston like the quench area does and that quench was .028.