Don Terrill’s Speed-Talk

Could be? This was all new stuff with correct angles and such installed as directed. I was just surprised at how much pressure(both sides best i can remember?) it was pumping back into engine. Maybe the high heat and conditions (circletrack many laps) helped cause problem. Had used them in the past with no noticeable problems but this one time system was causing problem so i quit using them.

I understand some of the aftermarket valves are inferior to the GM ones...

This could be!