1) the exhaust port is in the same location. 2) the head is overall taller than say an Eddy RPM. 3) The rocker shaft is moved up. 4) A Hughes Rocker lines up with the valve tip. 5) They have more potential than a fully ported Eddy RPM. 6) Sounds like you can use a 1.6 or 1.7 ratio rocker
Will 3/8" pushrods fit with higher ratio rocker and not require clearance ?