'94 Cutlass Ciera S 3.1 SFI V6 Piston Slap Issue

Hello,

I've owned my Cutlass Ciera for almost a year now, and when I first got it, it ran fine, plenty of zip, and I knew Piston Slap was standard with these engines, and when it warmed up it went away. Over the year, I've noticed that the Engine must get hotter for it to quiet up. Around July I noticed that it was still knocking within operating temperatures, it only quieted up when I ran it extremely hard. Now the piston slap never stops, even when I go ham on the accelerator. When it gets higher in the RPM range, there's this distinct whine as well. Engine has 149.1K Miles on it. When I changed the oil back in early June, I noticed a decent size peice of metal come out in the oil, approx 5mmx5mm as well as what appeared to be some small rocks.

How long do you think I've got with this engine? *All of this has happened within 2K Miles, I've changed the oil about every 750 Miles Since I got it.

Without knowing what those pieces were how do we know what's what? Were they aluminum?

I'm not quite sure, I never looked super carefully at it, but it was slightly green and had a slight curve to it.

Not much to work with here, the only green parts I can think of are valve seals they would be about 3/8 in diameter, when whole.