Transmission Pressure Gauge

[Trevor]

I have in mind permanently fitting a pressure gauge which I have on hand, as a means of constantly monitoring line pressure.

A plug is provided in the transmission casing for this purpose and I hope someone will be able to advise the thread and size involved. If need be, I can I hope source a plug from a dumped transmission and modify this to work as a connection. However it would be nice to be able to purchase the correct item from a brass fitting supplier.

It will be obvious that I do not wish to purchase the Subaru test part from a dealer, my wallet is not bulging.

Another point requiring an expert opinion, is the restrictor hole in the gauge I have, which is mainly intended for use with gas. The hole damps the movement of the pointer. When used with transmission fluid without an air lock adjacent to the gauge, the damping may prove excessive for my application and the existing hole may be best enlarged. What do those with hydraulic experience advise?

Special thanks in anticipation, Trevor.