Chattering noise.. search narrowed down.

Has the car been sitting for a while? Reason that i ask is that when i started driving my car before the resto, after it had been sitting for 15+ years, it started to develop a ticking noise at the front of the engine. It was a little diferent though, it would go away under a load (or maybe i couldn't hear it because it so darn loud @ wot) but it was definatly noticable under light throtle acceleration up to about 3500-3800 RPM. When my dad and i pulled the mill a couple weeks ago and started taking it apart, we found that the rod bearings on cylinders 1 and 2 were flaking apart. The only thing we can think of is that the acidity in the oil broke down the bearing surface while it sat. Then when we started driving it again, it slowly started to kill the bearings at start up. This created enough play that the #1 & #2 pistons were coming up and hitting the head. This is my 2 cents