[Boog]

Some times we get too focused in on one area of suspicion when the problem is actually non related.
We had a 77 Impala that developed a hard tick. I was sure it was lifters. Had to be one of the rocker nuts worked off or lift failed right? No, before I tore into it I used a piece of hose to locate the sound. It turned out to be the fuel pump. I guess the spring in it got weak. It was not an AC pump and not very old. A new AC pump took care of it.
We had a 75 Elcamino wreck we rebuilt. Low mileage car but had an engine tick. It turned out to be the dist cap was not sitting on straight and the rotor was clipping the terminals on one side of the cap. The dist cap got dislodged in the accident.
On one of my LS engine'd trucks, it developed a noticeable tick. That one turned out to be a torque converter bolt had backed out and the head was touching the engine block. Only one loose and it was very noticeable.