I just mocked up crane iron rockers, crane gold with roller tip, and oem stamped rocker just for interest.
With valve closed the Crane iron rocker contacts the valve stem at near stem centerline (see Photo). Rocker contact "rocks" toward exhaust side of valve stem, then the rocker starts to drag back across the valve stem at about .35 lift, for sure by .4 lift. The geometry is no good.
Crane Gold with roller tip contacts valve stem just to intake side of stem centerline (see photo), then rolls just to exh side of centerline, then by .5 lift the roller is sweeping back toward centerline...at .6 lift roller looks close to centered on valve stem.
OEM stamped rocker was similar to Crane iron....contact started near valve stem centerline (see Photo) and by .3 lift rocker was on the exhaust side edge of valve stem with geometry getting worse with more lift.
I then compared the Trick Flow intake port short turn to OEM 906 and Dart 230cc sbc. Photo of results is attached.
