I never said it was a good idea. It was the only thing I had handy to test with. I didn't leave it in place.That is one gauge that will never be used for diving again.

. I took 2 oil rail plugs drilled them out and then cut 2 3/8"ID an-6 heads off and tigged them together. bam threw it on a hydro to 6500psi. held for an hour! there you go homemade adapters (1/2in straight thread o-ring to an 6 fitting) . bend some staineless tubing/flared it(hydo"d the whole setup to 6500psi) . not bad for just a few bucks. Even if its a fad of the past, it made the engine run a little smoother @ idle.