349 CI on the cheap

Jack,
I guess he was thinking that the valve is a full lift at TDC and at this point the valve would hit the piston.

Sort of - I assumed the valves and pistons would play "tag" with each other.

I have two more questions.........

At TDC both valves are closed...so this clearance issue only occurrs on the "overlap" or second cycle of the crank, correct?

Also - In your experience what duration and lift would you say that this all starts getting too "tight" for a zero deck fly cut slug with an open chamber head?