Setting valves on a 430

[case 430]

I have a 1965 430 that recently developed an engine miss. After replacing plugs, wires, and going to electronic ignition, I ran a compression check last night. I found:
#4 130lbs
#3 135lbs
#2 125lbs
#1 40lbs and pushing compression out of the exhaust.
I couldn't find my feeler gauge but I noticed the rocker arm on #1 exhaust seemed tight with no clearance. I backed off the rocker arm and did another compression check and #1 came up to 100llbs. I bought a new feeler gauge this morning and plan to set the valves tonight. Any ideas as to why #1 exhaust would have gotten too tight?
Thanks for any help.

 

[Bob]

ASSUMING the last guy set it right, the only way they can get TIGHT is from a "tuliped"/overheated valve or valve seat recession into the head.