Go to this site and print the jic identification sheet off

https://www.surpluscenter.com/Tech-Help/Hydraulics/Thread-Identification/JIC/

You have either jic 6 or 8 most likely going into the valve. Whichever it is go back on their site and get a tee with fittings to hook to a 3000 psi gauge. Hook that up and see what your pressures are doing at idle,driving, loading etc. this will help us know where to look for the issue

Machine Builders Facebook Page
https://www.facebook.com/groups/1153014311474457/

Report site issues on the FB page if you can't on the main site.