Duration and cam timing play a big part in piston to valve clearence. That said we run the MP .557 cam on a 105 centerline in my sons 400 with alot of room as his eng had over .150. The KB pistons have a nice valve relief in them. I would think you will be fine but of course you will need to check it to be sure. Ron

Last edited by 383man; 01/03/09 06:27 PM.