Please tell me your gonna adjust those valves first before doing a conmplete valve job! Maybe the threads are stripped on one of those rocker studs at #5 cyl. I'm assuming you did a static test also. If you adjust the valve and get compression back then all well and good but get a mechanic to do a leak down test anyway, Ive had engines show 200 psi on all 8 and still have bad rings. think about it!

The valve spring was broke on #5. Running much better now after valve job and new springs.