119K mi 08 Chevy Suburban 5.3 L P0300

[Witsend]

Basically a dead miss on Cylinder 1 with ridiculous misfire history count. Cylinder cranking amps test showed a compression deficit on #1. Engine vacuum test with vacuum transducer showed fairly decent engine vacuum but missing a vacuum hump for #1. Checked actual #1 compression only 30 psi. Put shop air to cylinder and feel some blow happening from crankcase , but nothing ridiculous, and intake and exhaust valves don't seem to leak much. Don't hear any loud tappet sound from top end either.Possibly got a Piston not coming up as high as the others from a bent rod from going through water or an intake valve that isn't opening? Will pull left valve cover tomorrow and take a look, I guess. From looking at vacuum display, Any body know what I should likely expect to find? #1 is the 5th row over