This is one old man's opinion and not criticizing in any way so please don't take it that way.
I think he jumped the gun disassembling it. There was more diagnostic work to be done. You're very vague in your terms talking about valve adjustment. Do either of you know the correct procedure for valve adjustment?
Again, not criticizing, only asking, because I have no way to know what either of your abilities are. Obviously, #1 has an issue. Could be a rocker out of adjustment, bend pushrod, bad lifter, worn lifter and or wiped camshaft lobe.
Before it was torn down, did he watch the rockers to see of all of them were moving the same amount? In other words looking for a wiped cam lobe and or bad lifter? This is some of the diagnostic work I was talking about. There's even more involved such as putting shop air into that cylinder with both valves closed and seeing "where" the air goes. You can diagnose a bad intake, exhaust valve in that manner. This is why I said I think he jumped the gun. Not the end of the world, now you just need different diagnostic procedures.
At this point, I would set the head up level on the combustion chamber side and fill #1 up with rubbing alcohol. CHeck to see if any leaks out into the intake and or exhaust ports. If it does, check the rest. If they do as well, it probably needs a valve job, or has some bad valves and or seats.
You can also roll the pushrods on a level surface and check them for being bent. A bent one will stick out like a sore thumb. Inspect the valve springs closely. Make sure you don't have any broken springs. Also look closely at the valve spring retainers and the top of the valve guides for witness marks. If the retainers are hitting the guides, this can cause binding and bend a pushrod.
These are just some of the things I would check for at this point.
Good luck. If you need some more help, PM me and I will be glad to talk to either or both of yall on the phone if need be.
