Update:
I built the leak down tester as described by Mike Niday??. The result on the 216 was NO cylinder over 60lbs and most under 20. 1 and 5 were about 5 lbs and were obiously leaking past the exhaust valves, as I could here it only at the tail pipe. #4 had sixty lbs and this was the only cylinder that had good compression (#110). The rest had some leakage thru exhaust valves and the crankcase. I slipped a piece of heater hose over the dipstick tube to ck for air in the crank case. I ran these test 3 times to make sure I was at TDC on all cylinders when tests were made and the results were the same each time. I then tested the 56 235 on the engine stand with no rockers installed. All cylinders were above 90 except 1 which was at 76. I could hear some air in the exhaust in this cylinder. I wanted to find out if the 216 had just head/valve problem or ring problems. I'm fairly convinced that it is worn out, and that I should concentrate my efforts on the 235. I am going to pull the head on the 235 and have it checked for cracks etc. I may try to lap the valves and install new seals. Since it is on the stand, I plan to pull the pan and ck the bottom end, install an new rear main and decide after I inspect the cylinders where else to go. I do not want to do a complet O/H unless I see something that really warrents it. I'm hoping that doing the valves will suffice, but I understand that disassembly will tell the tail.
