I put a new set (two years ago now) of Harland Sharp 1.6 on my Eddy RPM BB heads, I had to grind on one (#6 intake port) head and ended up putting a hole in the side of the #6 intake port CNC ported heads
I had it welded up and it is fine now
my Harland Sharps check at the retainers to actually have 1.64 ratio instead of 1.60
I have another set of Harland Sharp 1.5 (twenty years old,
not much use on them
)that are on a unported set of Eddy RPM and they fit fine, no mods required
I also have a set of Indy SR heads that I put a set of T&D 1.65 rockers on and they needed grinding also, no holes on them
IHTHs. BTW, the change of rockers did help that motor,
The old set of CAT rockers checked at the retainers to be 1.46 ratio instead of 1.60