1973 340 issues.

So after leaving 50/50 mix of Acetone and ATF in the bored over night and today running a can of Sea Foam in the carb including two hot soaks I get the figures below.

Cylinder #1 = 115psi
Cylinder #2 = still 35psi
Cylinder #3 = 110psi
Cylinder #4 = 105psi
Cylinder #5 = 105psi
Cylinder #6 = 85psi
Cylinder #7 = 110psi
Cylinder #8 = 105psi

I squirted in a tablespoon of oil into bores #2 and #6. No difference on bore #2 but bore #6 jumped from 85psi to 95-100psi.

There is a dark patch on the Headders by Port #4 when cool I felt it and it’s greasy. There is also smoke around that bank too so maybe the head gasket is bust?

When I did the Acetone/ATF soak Bores #1 and #7 boiled/bubbled the mix when added. Only those bores though. Poor coolant circulation?