[tooski]

Just before I shut it down and escaped the winter for a few months, my engine developed a problem. I think something is going on with the lifters. They are 1980's era VL 11 from HO Racing, along with the HC 02 - HO 744 HL cam. Modern HS 1.65 rockers. ~ 520 @ valve.
Luckily it happened just as I pulled into my garage. Just as I shut it off I heard a tap.... tap..tap tap. I restared it and it went tap.. tap..tap.tap tapitty tapitty tappity. Shut it down. Sounded like it was coming from the top of the right side of the engine as opposed to a heavy knock from the bottom (rods). I took the valve cover off to check the rocker arms. A couple of them felt loose and I was able to depress the push rod ends a fair bit. I thought, crap, cam lobes.
Today I started to get on top of it. Exposed the lifter galley. I randomly checked the lifers, not all. For example, I brought #8 to tdc (it was closest). Both lifters on base circle. The exhaust lifter was hard and I could not depress it. The intake lifter was soft and I was able to depress it. I checked others that were on or close to the base circle. Same results. Some were hard, others were able to be depressed, some easier than others. Of those some depressed farther. I did not make notes as to which, just trying to find a commonality. I also rotated the engine to see what the lifters do on the nose. Again, some of them the plungers depressed a significant amount while others only slightly.
I then spun the oil pump up with the pre lube tool. Steady 68 psi. The ones on the nose were rock hard to begin with. The ones close to base circle became hard but began to soften as they bled down. Some stayed hard, others I was able to depress, some easier & farther, others stiff & only a bit. Again, I did not take notes, nor did I check each lifter on base and nose. Just trying to see if all acted the same.
When I was running the oil pump I saw oil exiting the lifter bores, but I got none to the top. Ran the pump three or four times, longest maybe 30 or so seconds.
And, the cam looked good to me. Pics if required.
BTW I tried the plug in the spark plug hole to find TDC. Worked well for me on my 461 in AZ. This 400 here at home - nada.
Thanks in advance for any info.
Frank M.