If nothing else pans out, you could click on
this linkEnter the part No. YT6023 into the search function. This is the Yella Terra part number for the whole roller rocker kit for A series Datsuns.
In fact it looks like being the ONLY engine part that they have listed for A series Nissan engines.
I bought a set of these on 30/07/04 & paid $696.55 for them plus Blood Sucking Tax of $69.66 bringing it to $766.21.
The $11.55 freight bill brought it up to $777.76.
If you can handle that, remember that you will need custom pushrods too.
These are lsted as being 1.55 to 1 ratio however the man at Yella Terra that I spoke to was adamant that that were 1.54 to 1 ratio. This is against the stock 1.44 to 1 ratio.
The 1.65 to 1 ratio rockers have not been available for some years.
It was a special order, so was non returnable & they are still listed so should still be available.
The damned cylinder head, complete with rockers & alloy rocker cover looks like it has cost more
than my KB10 coupe did when it was new.
The things we do.
EDIT
You could also
click on this & navigate your way to
here to see what they have on offer.
This page will also help you find a place where
you can buy this stuff.[It's amazing what a few moments with a search engine can find]