Hughes Engines 1.6 Rocker Geometry/Setup

This was a built-in feature of the SB engine & Chrys didn't charge extra for it!
There is simply not enough room for the stiff/big valve springs reqd with bigger cams because of the short rockers.
Yes, grinding the alum rocker is an option but you are grinding the rocker in a very heavily loaded area, where the load has already increased because of the stiffer springs.
Other options:
- use beehive springs or maybe smaller diam springs
- use steel/ductile iron rockers which do not need to be so thick in this area.