.660" Valve Spring Kit for early 5.7 & 6.1 Gen 3 Hemi

.660" Valve Spring Kit (PSI 1516 or PAC1276) for Early Gen 3 Hemi 5.7 & 6.1 engines.

This kit includes:
 

• 1 set of 16 Premium .660" Single Beehive Valve Springs (1.290 OD 150 lbs @ 1.800" / 420 lbs @ 1.140)
• 1 set of 8 1.250 OD;.875 ID;.060 Thickness Intake Valve Spring Shims
• 1 set of 8 1.250 OD;.875 ID;.030 Thickness Intake Valve Springs Shims
• 1 set of 16 Valve Spring Locator/Seats
• 1 set of 16 Valve Stem Seals

Optional Upgrades:

• 1 set of 16 Steel/Titanium Upgraded Retainers with valve locks

SPRING SPECS:

• 150 lbs @ 1.800"
• 420 lbs @ 1.140"
• Coil Bind @ 1.080”

*NOTE: This kit uses a .090” shims under the intake valve spring to achieve proper valve spring installed height. No shim is needed under the exhaust valve springs.

**NOTE: On early 5.7 and 6.1 Gen 3 Hemi cylinder heads, do not exceed .600” intake valve lift and/or .580” exhaust valve lift unless you machine the valve guides for the needed additional clearance.