My c/n 062 heads have plenty of clearance and the tips are
not 0.290- which is supposed to be only on the exhaust, anyway. I suspect the valves were resurfaced and this caused the tip lengths to be shorter than 0.260" intake/0.290" exhaust. The rockers clear them just fine. So the tip length is not
ordinarily a problem.
If this was a universal problem, there would be thousands of reports of this being a problem. But there aren't- because it
isn't a universal problem. There's something peculiar about HIS set up that is causing the problem, I believe it's the rockers he's using, or the geometry of the valvetrain (which hasn't been addressed
AFAIK).