The best candidate for a higher intake rocker ratio is:
1. under-cammed
2. does not need exhaust duration bias (longer exhaust period)
3. wedge chamber with shallow stem angle and valve head close to the bore
4. has enough head capacity and lower end strength to operate at higher RPM
5. not coil bound at new lift (or new springs)

Your porter's input is very valuable here as to relative port capacity in/ex.