[Russco]

Ok so I tried the test described above, the left bank did push water out and showed some bubbles. (After a few minutes the right bank also pushed a little out but nowhwere near as much as the left bank) I think it may have been just water expansion it was getting upwards of 190-200 on the gauge by then. Anyways I bit the bullet and pulled the left head off.

I can't see anywhere it was leaking at all. I can't see any cracks even the usual bolt hole cracks are not visible. Here are a few pics maybe they are good enough to show something I am missing.

Edit: on the bright side I found it has a 4 inch stroke. (which explains why it pulls better than my 239 in my model a coupe)