I recently replaced all of the lifters in my Magnum 5.2 with new ones from Sealed Power just for mileage sake. There was a light tick in the engine on the originals.

The new ones seem to have one lifter that does not stay pumped up when the car is off - it always goes clalalalack when I start it.

After the car is running, you can't hear it too well at idle, but it stays around all up and down the rev range, as if the lifter isn't pumping up the last little bit either.

I have made sure that all of the rocker pedestal bolts are tight and replaced the header gaskets on both sides. I also checked to make sure I don't have any loose or cracked spark plugs - nope. Neither of my header gaskets were blown out (I couldn't tell from the sound, when I blew out a gasket earlier it made a similar noise).

I tried adding some Marvels' Mystery Oil to the engine in case some lifter bore scuzz messed something up and this actually improved this behavior by a bit than when I first started, but I still can't get the tick to totally go away.

I also pulled all the pushrods back out to make sure they're clear end to end, which they are.

I'm suspicious that I may have a slightly bum rocker somewhere since I had a light tick somewhere in the heads/valley before I changed the lifters too. I have read about rockers occasionally being wear items on these motors.

Is there an easy way to check the rockers without a known good spare pair on hand? Is there anything else I could be missing? It is 100% definitely somewhere in the engine itself, not the tensioner or a plug wire arcing.