Low compression

[70c10stepside]

Hi all. My 355 I've realized a ticking noise come out the exhaust. Sounds like an exhaust leak but coming out the pipe itself. So readjusted the valves and it was still doing it. I've narrowed it down to the #7 cyl because it keeps killing plugs. But in away I've never seen. The plug gets pretty lol like really clean. With a slick texture to it. Well, when I done the compression test it read back 60. Squirt a little oil on the hole and it came back 90-100. Rest have 160 to 170. Motor is around a year old. Still has soft seats and that head. Other side lost seat but happened suddenly. And none of these other signs came with it. It just happened. It's 68 327 double hump heads, flat tops which may put it 10-5 to 11. So all the builders have told me. I had been running a vp mix with it for awhile to give lead and that little more octane. But didn't last fill up and here we are. Awesome right? Thoughts? I give enough info?