Is there valve seal clearance problems with an Isky Stage III (.490 lift) cam? Or is that the maximum lift possible without valve seal mods?

Depends on the height of the valves in the head, the depth of the seats, etc. but you usually run into issues around .470 or so. Easy fix with a much better seal detailed here: http://forums.hybridz.org/showthread.php?t=90825

Thanks Jon........I appreciate your knowledge and help. Happy New Year! Guy