FED LS DUAL SPRING KIT .660" LIFT
FED LS DUAL SPRING KIT .660" LIFT
FED LS DUAL SPRING KIT .660" LIFT

Frankenstein Engine Dynamics

FED LS DUAL SPRING KIT .660" LIFT

$450.00
Cylinder Head and Guide:OEM .505 Powder Metal Guide

The FED Dual .660 spring kit is a great option for LS aftermarket performance engines. This spring kit works great for high-RPM, N/A power, and boosted setups. Frankenstein and PAC Racing worked together to bring a very versatile spring that outperforms the typical polished .660 springs on the market. We offer this spring kit for stock valve guide (.505) and bronze guide (.565) applications. 

These use a high-grade titanium retainer, black oxide steel locator, and 7mm GM valve locks. Our spring kit is a drop-in for stock heads and aftermarket heads.

Kit includes:

FED .660 dual spring (16) 

GM LS locks (32)

Titanium retainers (16)

Locators for stock or bronze guides (16)

Viton High Heat Valve Seals (16)

Spring specs:

FED .660" Lift Spring Kit

  • Installed Height: 1.800"

  • Seat Pressure: 149 # @ 1.800"

  • Open Pressure: 396 # @ 1.140"

  • Max Recommended Lift: .660"

  • Coil Bind Height: 1.085"

  • Spring Rate: 375 lbs/in

  • O.D.: 1.293"

  • Outer I.D.: .948"

  • Inner I.D.: .670"

Spring Pressure by Valve Lift

  • .575" Lift — 358 #

  • .600" Lift — 370 #

  • .625" Lift — 380 #

  • .650" Lift — 390 #

  • .660" Lift — 396 #