Does anyone know why RB did not use an offset exhaust rocker (as are his intakes and both factory intake and exhaust rockers)?
Examine the (HT: 6PKRTSE: great, thanks) picture of the blue RB set. The intake shafts are parallel to each other and the crank axis, and 90° to the valve stem axis. Since the valve stems are only canted in one axis (cross plane, 90° to the crankshaft), the rotational path of the rocker's tip is in the same plane as the stem
The exhaust shafts are skewed at a shallow angle (appears to be 22.5°) to attain alignment with the exhaust stem tips. When the rocker oscillates, it does not push the valve straight down, but at 90° to the shaft axis, and the roller scrubs sideways on the valve stem tip.

Ideas?