SP604-20+ "Hand-picked' 604 Valve Springs

These genuine GM 604 valve springs are hand-picked and tested.

The springs are batched and matched separately for intake and exhaust and meet our standards for controlling the valve at the highest RPM possible for “legal” valve springs.

Our intake springs (red tie) meet the high-end specs; our exhaust springs (white tie) are three to four pounds less than the intake springs.

This is due to a difference in weight of the two valves and in lift from intake to exhaust.

This process maintains a better balance in the valve train.

All springs are coil-bound three times before testing to set the metal.

Springs are inspected for square and then rated at open pressure.

All springs are from the GM 19420455 and in no way aftermarket or 'cheater' springs.