Valve bucket lifter and timing chain tensioner.
 

So i got the dreaded ticking noise. After months, I finally decided it to take it to my buddy's house and tear it apart. Got the timing cover off, cams out, and sure enough, one single lifter is almost a millimeter out of spec. I've heard this is a common problem with these cars, but my question is why would the lifter get damaged like that? Should i look for anything that would have caused this? Or is it just random wear and clean it out best i can and lube it?

My other question is when I took the timing chain off, everything looked great, nothing looked worn, the chain was tight before I took it off. But when I took the tensioner out and took the pin out, it didn't seem like it wanted to reset. Should i replace it, or should I expect that? i seem to recal it uses oil pressure to work, so should it be fine after installing again?

Measure the lifter gap, measure the lifter bucket, order a new bucket with the correct spec. The tensioner is probably fine, when you install it just push a little tension (not too much) and oil pressure does the rest.

Yeah I measured the clearances of all the lifters, only one was out of spec. Then I got it out and it's the only one that is indented where the lifter sits on the valve. What I'm asking is, is this a symptom of something else? Is there something that would cause that lifter to wear, or is it just "normal" wear?

Sorry for the late response, normal wear. Probably was at the high end of the spec during initial assembly and over the life of the engine it's progressively gotten a little worse and a little worse, imagine taking a hammer and holding it 1 inch from a nail and trying to hammer, it would take a LONG time to finally hammer the nail down, now hold the hammer 6 inches from the nail, you can hammer it in much easier even though it would still take a while. Same principal.

Yeah, I figured. I just put in a new one anyway. But see if you can answer this. Got everything back together, idles perfectly, there's no exhaust on it at the moment, but I took it for a test drive, and it ran kind of rough and even stalled on me once. Would this be because it has no exhaust? Like not even cats. I also have to do the throttle relearn too, would that cause it to stall?

Throttle relearn would be the more likely culprit but you end up with all sorts of issues not having pipes hooked up so I'd wait until you have the exhaust back on then do ALL the resets and see how it performs then.

Nah i found out what it was. It was the grounding wire where the engine cover bolts on, it wasn't attached very well and was making a bad connection causing it to bog.