[Rick Parker]

If I had to hazard a guess it would be the wristpin area of the piston. As the RPM's escalate on these engines (close to 10k for pushrod motor) they continually lighten the recipricating weight of components and by doing so reach an area with unknown results, regardless of dyno time. Pistons by nature are the first thing to look at as they travel up & down (duh!) inside and stop and reverse direction at the top & bottom of the stroke. Their weight or lack of it it directly transfered to the rod. Allowing for quicker acceleration because of less weight. But as they are removing material to reduce wieght, strength is compromised at some point. These guys are closing in on 850 Hp and 9600 rpm in non restrictor plate trim.
This is real punishment, and pounding for hours at a time.
Thats my story and I'm sticking to it!

Rick