Stock rods with aftermarket pistons???
Seriously, there are quite a few available aftermarket pistons designed to be used with stock rods. Wiseco, Lunati, etc... Nothing too special about them at all.
As far as breakage, the stock bolts are most definately the weak link here. I believe stock rods would be fairly reliable at ~7100rpm or so with good quality (ARP) bolts.
Hell, mine lasted ~2 years with stock bolts, racing 1-2 times a week, and was put together by me in my garage. Just imagine if it had been done right... <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

