hey Mike, that's about rite, I can't remember right of of the top of my head ,but it seems that it was close to an inch, so your in the neighborhood,if you want me to make sure let me know?
ok if the water pressure is 20 psi at 3 grand then its getting to high at WOT ,so I would check the t -valve to see if everything is working rite,the ball and spring sometimes gets trash in it or its rusts, if it's rusty trash it!! and get new ones ,does the water shut off at idle??and the steam stops?if it does then thats ok ,next try to add a bigger or extra dump line that will bring the pressuse down so the tee won't open so soon and your block pressure will come down to like 5psi at 3 grand try that !!
I had the same problem the first time I went out, the pressure was 65psi at WOT, so I added a extra dump line cause the dump line was to small (8AN)then I went to the same size line as the inlet (10 AN) and solved the problem! give it a try ,let us know how it turns out!
Markist