These Box Stock class valve springs have been specially treated to prolong pressure retention. The pressure loss from fatigue is about half of what is seen with untreated springs. This will allow the engine to run a higher RPM for a longer time before experiencing uncontrolled valve float, requiring spring replacement.
DJ-1055PS are checked and preset in house to meet AKRA technical guidelines.
The springs are made in batches of thousands of springs at a time and are designed to pass both the 10.8lbs @ .850 and the 18lbs @ .650" check. We have not found any that failed after dyno time, however, we do not guarantee they will all pass tech out of the box. Sold in pairs
It is always a good idea to check BEFORE tech!