Lifter tick won’t stop!!!

    It’s not often that I get stumped but by 72 Gran Torino sport is absolutely cursed. If it wasn’t a one of one car I’d have sold it by now. After figuring out quite literally 6 or more issues all I had left was a lifter tick. Easy right? Upon further inspection it was not getting any oil through the rocker arm on the cylinder with the tick and adjusting it wouldn’t stop the tick I ended up replacing the lifter with a new one and put in all new roller rocker arms. The push rod was straight and clean. Installed with lube but not “pumped up” so I wasn’t surprised when it ticked when I started it up. I had initially set it with a half turn of preload after contact on top dead center. I ran it with my test valve cover on it and loosened it until it clattered like mad and revved it up for a minute or so to make sure that it was oiled. I was now getting oil through the lifter but when I gave it a half turn after the clatter subsided it still seemed to be ticking a little. I verified this with a stethoscope. I went a little more and then a little more. And at best it was quieter at certain RPMs but was still making noise and it seems I have too much preload now as it is running rough. When I loosen it up it smooths out but ticks louder. I’m going crazy here. It’s a 72 grand Torino sport 351CJ 4 speed with with a comp cams extreme energy cam, hardened push rods, adjustable valve train with nylon guides and roller rockers. Any thoughts before I put a third lifter in the same hole? Thanks

Sticking valve perhaps?
Had it in my first 351CJ in high school. Ended up breaking a pushrod.

It has the screw in conversion that does not require machining and the tick is only on number eight intake side. It can be easily verified with a stethoscope that it’s the only offending valve. This was a complete rebuild and the heads had new guides valves and seats. I am going to contact comp cams for suggestions, however if it was a design issue it wouldn’t be isolated to a single valve. What makes me crazy is that from loose to too much load it still doesn’t stop ticking and I have changed the lifter and rocker. I am now wondering if somehow it’s a loose seat but I have never heard of that and I would think there would be another indicator. I will next check the lift of each lobe and see if there is a difference and post results.

weak or broken valve spring?

I think I may have figured it out, at least I hope so. I know had to of had a bad lifter as there was no oil at the rocker arm. The new lifter cured that but I still had a tick that I couldn’t adjust out. When I took it all apart I could find anything wrong with the pushrod, rocker, spring or valve. I rapped the valve up and down without the spring to see if the seat was loose and dropping somehow but it seemed fine. When I went to reassemble the rocker arm shafted looked as though I may have put it in with the round side up instead of the flat. I made sure it was installed properly and for now the offending noise seems to be gone. Thanks so much to everybody that chipped in to give me some ideas. Just getting a different perspective can really help.