My 1st stovebolt engine (and still the current powerpalnt for my 49 3100), was a 216 that sat for over 40 ys.
Similar to yours I had very low compression in 3 cyls and too low compression in the other 3. Needless to say it wouldn't run.
Pulled the head and all the valves & seats were burnt and would seal. Luckily it had no cracks.
Had the head checked & rebuilt for around $300 (all new everything) and it runs like a singer sewing machine.
I'm currently in the process of rebuilding a 54 235. It had 0 compression in cyl 1 but the other 5 were above 100. Pulled the head and found piston #1 with a big ole hole in it.
So to shorten the story. I doubt you'll get acceptable readings even w/oil squirted in the cyls. The dry readings are just too low.
If you know for sure that the valves are fully opening & closing and you ran the test w/the throttle plate wide open then you're going to have to pull the head and inspect.
You'll find many differing opinions on installing hardened valve seats in these heads. I had them put in mine but many will tell you they're not needed. That'll be your call..
Once you get the head off and inspected you'll know what you'll need. I recommend to take it to a machine shop and have it magnafluxed and checked for cracks. No sense in putting $$$'s in a boat anchor head...
I'll be dropping my 235's head off sometime this week or the next for the same checkout.
Good luck
Dave
