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Valve stem sweep starts just outboard of the centerline of the valve, then continues out from there to about 1/2 way to the outside edge of the valve (so 2/3 to 3/4 to the outside of the valve.
Thanks for the input, standing by...

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If, when using a solid test lifter and the valve closed, the rocker to valve stem contact should start on the inboard side ( closest to the rocker shaft ). If the contact starts on the outboard side, the pushrods are too short. Ideally, you want the rocker to wipe equally on both side of the valve stem center line as the valve is lifted through the entire travel.

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John, how does pushrod length affect rocker geometry/sweep pattern?

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I have been wondering that too. The pivot point on the rocker shaft remains constant. all shorting the push rod will accomplish is is to lessen the preload on the lifter and if way too short create lash on a hydraulic cam or excessive lash on a solid lifter cam. It won't change the rocker pivot point center to the valve tip.

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First, just to clear any confusion, on a fixed shaft system, pushrod length ( by itself ) will not change rocker arm geometry - but in order to have the correct rocker arm geometry, you usually have to change pushrod length (if you are going over 1/2" lift - and for sure with a valve stem height change). You need to be looking at both sides of the rocker arm. With the valve open 65% ( small block )of the total valve lift, the rocker to valve stem contact should be in the middle of the valve stem. At the same time, the rocker arm adjuster screw ( set to show about 1 thread below the rocker surface - or the pushrod cup as close to the rocker as possible )should be in a straight line with the pushrod. Seldom can you get both parameters right without shiming the stands ( draw back to fixed geometry system ) and changing the pushrod lengths. You will also have to contend with rocker to spring retainer clearance issues. Although I think shaft systems are much more stable, Magnum ( chevy ) style systems are much easier to set up - usually just a pushrod change. Sorry if my previous post was confusing. I was basically addressing the fact that his valve stem to rocker contact point ( with the valve closed ) was on the wrong side of the valve stem.

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