Well, as far as the pistons go: GM switched to forged units with shorter
skirts on them starting with the 2001 model year, hence the racket on a cold
startup (3.1 V6). But nothing says lovin' like the sound of bend con rods
either, so I'd consider switching out anyway. Not worth trashing the block
over who-knows-what-they-were-thinking in the quest to save a few
dimes-per-unit at assembly time. Besides, I wouldn't count on the crank
being forged in these mills either. I guess the question is how long do you
want the modded engine to last?

Cheers,
Andy