Aye, I third the no piston to valve contact thing, but actually my small block still runs with 4 bent valves. YAAY!........Not that that is a good thing to do but it does move under its own power....I had to get it from the middle of the yard somehow and its ALL uphill to the garage. But yes I would imagine that either the springs are binding or those rockers (which I was warned about when I built my SBC) DO NOT have enough clearance for that much lift, they are likely hitting the stud which could screw up the stud too though. tech gave you good advice, check those things out real closely and decide what is binding.