Naturally, I've been thinking about this constantly. This may explain a lot of small things I noticed since I put the new clutch in and have been joyfully driving around in the old Cobra II.but I found out soon after that it was indeed crankcase pressure necessitating the tear down.
When I went to the exhaust guy and while he had it up on the hoist I noticed that there was a fresh oil leak coming from the left side of the block near the front. I looked close and it appeared that the oil filter was leaking just a small amount. And, from closer inspection, it also appeared that the fuel pump was leaking from the bottom of the gasket. Which matched up with the drops on the floor of my garage. Also, earlier when I was changing the clutch I noticed that the oil pan had fresh oil on the bolts. At first I thought the rear seal was leaking but it wasn't the seal. I just thought it was residue from the blown power steering line or I thought those gaskets were old and possibly just weak.
So, when I got back from fishing I was determined to get rid of the lifter problem. Which I did by pulling the covers off the lifters and starting up the engine and doing a visual on the rockers. It's hard for me to hear where the noise was coming from but in a few short moments I determined that #8 was the big problem and #4 also needed to be tightened down. Gone was the noise. (Happy Camper) But first I replaced the fuel pump and gave the oil filter a little extra twist.
That was just before the horror on the highway.
I'd like to determine whether I have excessive crankcase pressure due to a broken ring(s) before I go through the replacement of the intake manifold gaskets. All the plugs look like they are burning perfect.
Is there a way to tell if there is a ring issue? Compression test? I've never done a compression test so I'd need someone to tell me a procedure to follow and I'll run out and do it.