Ok, I think I've found the problem.
Just so you all don't think I'm crazy,
here's a video showing how easy it is to push the #5 exhaust valve open. The #5 intake is the same.
I also looked down the valve springs on all the exhaust valves and noticed that I can see the valve spring seats at the bottom of the other valves, but can't see one on the #5 exhaust valve. The valve seats are the cad-plated yellow color which makes them easy to spot against the aluminum. On the #5 valve, tho, I can just see the aluminum seat the valve spring assy sits in.
A valve without a seat would explain why its so easy to depress and would likely float to kiss the piston (hopefully a very tender, gentle kiss).
Does anyone in MA have the intake and exhaust valve spring compressor tools I could borrow?
Thanks.
Geoff