So I'm having a problem with my 350. Its got about 15000 miles on it after a bottom end build, heads were not rebuilt. It has full roller rockers, comp extreme energy hydraulic flat tappet cam & lifters, scat forged crank, edelbrock intake and carb. It has a couple known problems;
-Passenger side header has a small leak that I can't find
-Valve stem seals are going bad (smokes on warm restart after sitting for a bit)
-Carb is on its last leg, inside of it has started corroding so it runs rough sometimes till I clean it

But I have been limping it along with these problems, just keeping an eye on things. Now it has developed a new problem. I noticed a tapping on the passenger side head, so I adjusted the rockers to 1/4 turn past zero lash thinking one had loosened. This didn't fix it though. The tapping sounds like its just one rocker. The strange thing is it only starts to tap after the engine has warmed up. So completely cold, there is no sound, but as soon as I let it warm up or rev it a little bit it starts to tap.

Now this sounds to me like a problem lifter, but I not 100% on it. Does anyone else have any ideas? Am I wrong on this diagnoses? I put some seafoam in the oil today and plan to change the oil next weekend after driving it a bit to see if its gummed up. Any input is much appreciated, thanks.

 

How is your oil pressure when it's ticking?

 

Oil pressure when cold is pegged at 60, once warm it drops to about 35. It will tap before the pressure drops, just not on initial startup. I've noticed that if I give it a couple small revs right after startup, sometimes it will start tapping.