Alrighty - made my mock up running rig and ran for a solid handful of intervals. My initial readings (which I listed in the first post) were taken while the engine was cold. Online I read that a hot test was more ideal, so I did that on my new test. My readings were roughly 20 psi lower than my first test, but the pattern was the same as the first test. Below is a link of the engine running which I uploaded to YouTube just because. After a water jacket flush using water, the results were muddy water (maybe some oil). All of these results combined are making me think head gasket. Seeing as I will not run this engine an extreme amount I am not going to change the gasket YET. I will put it into the truck when it's ready and then I can make the change down the line.
Leak down test will be done tomorrow.
Cheers
Youtube video of engine running
