Dead cyl's on BBF

This is the motor in the 65 I bought back in the summer. I parked it abut 2 months ago to start work on it for the winter.It is inside warm and dry. I went to start it.Starter just grunted,checked battery it load tested fine.Had a old style ford starter that had been dragging anyway, so I change the starter to my back up gear reduction.It still grunted but this time a little gas dripped from the header collecter.I pulled plugs blew the gas out of the cyl's used marine fogging oil in all 8 turned it over a few times fired it up it sounds awful pops like have plug wires crossed this is right bank cyl 5 thru 8 make sure nothing is crossed run compression test which shows 150 to 155 lbs on every cyl. put new plugs in no change. cyl 5 6 7 are dead 8 is fine there are no rocker arm or push rod problems. no broken valve springs.I haven't pulled the intake yet but valve lash was good on all cyl so I don't think there are any broken lifters . there seem to be proper movement in valve train when it turns over.The plugs are firing on these cyl. It ran great before this???? Any thoughts ????????? Oh yes it is a low comp dish top 466 and comp. #'s are normal for tis motor. Thanks for any help. just want to cover all bases didn't have a plan to tear tis one dowm over the winter.

Do a leak down test.

Snake treed me...............

My car did that last year.Had two dead cylinders. It was the rings

The valves aren't seating and gas filled the cylinders. Also,cheap,low octane gas will seize a valve in the guide. Do like Blake said,do a Leakdown.

I don't have a leak down tester but I will get one tomorrow.

Got it back on all 8. It was a series of things one plug wire was bad.The folks I bought it from had the plug wires # but they wrong in the order they go on the block.I had not noticed this before.So that was it. I still plan on a leak down tester something I should have had one a long time ago. Thanks for your help Ward