750/850 pistons

where is the difference that causes 750 pistons to have valve reliefs and 850 pistons not?

850 pistons have a lower deck height than 750 pistons ( about .070" lower), to reduce the compression ratio. As a result, they don't need cutouts for valve clearance, at least with stock cam and gaskets.

Ken

thats what I figured Ken, just wondered why the 750 valve pockets are cut so deep
Don