Alright, its been a while but I am finally back at it. I went through and readjusted the lifters. They quieted down a little bit but there was still one trouble maker. I then took the truck for another drive and then attempted to compress the lifters. They all put up a good fight and took longer than a minute to bottom out.
I threw my vacuum gauge on it when it was cold and got this:
The needle is rapidly waving about in a 1/2" - 3/4" range. Doesn't that point to worn valve guides? With the engine still cold (and clacking) I tried to compress the lifter and it still took well over a minute to fully compress.
What is odd (to me anyhow) is that once the engine is nice and hot the gauge was much steadier.
When warm the loud clacking also turns into a quieter (but still very noticeable) tick.
