Shot - and a goal!!! Congrats azmopardart. U should be in the 12's before you know it. As to the valve train geometry issue: You are right moper - regarding the constant relationship between the pivit point ( center line of the shaft ) and the rocker to valve tip contact when the valve is closed - and this aint good when you install a cam with condiderable more lift than what the valve geometry was intended for. At full lift with a higher than stock lift cam, the point of contact starts to get real close to the edge of the valve stem, often doing some major side loading to the valve ( reads wears out guides and rockers ). The geometry change takes place on the push rod side. the distance between the lifter cup and rocker cup changes (remember I did say slightly ). This changes the push rod angle ( already crappy on small blocks ) between the two points and that in turn changes both the lift and duration of the cam. Changing the aformentioned relationship between the rocker tip and the valve stem to accomidate a higher lift cam can only be accomplished with a valve length change ( as moper stated ), shaft shims, or lash caps. Ok, now that the problem is solved, time to get busy on that 5/16" to 3/8" fuel line change----