I have, for my part anyway, resolved this issue. I ended up tapping the block hole for 3/4"-14 NPT and used an NPT-to-AN fitting (-10 AN) from Evil Energy so I can run a hose from the block to a vented catch can. I've also done something similar for the valve cover breather tube which I also intend to run to the same catch can.

I plan to write up a technical article on this.

Just for reference, currently on Yahoo Japan auctions is a Nismo/sports option oil catch tank. Whether its exactly the same as HS30-H mnetioned earlier in this thread, I am sure Alan can confirm.

https://www.jauce.com/auction/k1231067797

Here is a few photos for reference when the link goes.

Edited May 27May 27 by RIP260Z

19 minutes ago, RIP260Z said:

Just for reference, currently on Yahoo Japan auctions is a Nismo/sports option oil catch tank. Whether its exactly the same as HS30-H mnetioned earlier in this thread, I am sure Alan can confirm.

https://www.jauce.com/auction/k1231067797

Here is a few photos for reference when the link goes.

Hi Ian,

Good spot! That's the slightly later screw-top type as offered in the (late) Sports/Race Option lists. I have one on my KPGC10:

Probably pretty rare, and it shows...