Working on a 1956 235 engine that I purchased used. PO said it was rebuilt 14,000 miles ago. It had been non running for about 4 months since I got it. Currently set up on a run stand . It starts and runs ok.
A compression check on a warm engine reveals:
#1 145
#2 60
#3 142
#4 150
#5 150
#6 162

I readjusted all the valves and added one and one half oz oil thru the spark plug on #2. Compression increased to 90 but then next time returned to 60 psi. I did a leak-down test on #2 and it drops from 100 psi to 40 and holds there. Rockers on #2 valves were loosened to close them. Sounds as though air is escaping through breather/crankcase. I Wondering what the next step is to further diagnose this problem? If I need to pull the head and inspect the cylinder/piston I may decide to go ahead and install my older 235 engine in the truck and make this engine a separate project. Any suggestions or advice much appreciated.

1953 3100 Pu