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Valve Spring Kit GT40, Low & Mid Lift Cams, Max Output Drop in, Up to .520" Lift

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Calculated at checkout

Product Description

Fits Factory Heads, no machining required.

Drop in Spring kit for: Mid Lift Cams. (.440"-.520")

Application: SB Ford w/ GT40 Heads w/ 1.6 or 1.7 ratio rockers


We continue to develop specialized spring kits to suit various cam profiles.

This version from our GT40 spring kit family is intended for low to mid lift cams. If your roller cam has between .440"-.520" lift at the valve, this is an excellent selection.

Our low to mid lift kits provide more open pressure at lower lifts and are a good choice for Ford's "B" & "E" cams.

If your cam and rocker ratio combo produce between .440"-.520" lift at the valve and duration is no more than 226 degrees @ .050", this kit is a good selection.

When running lifts in the .440"-.520" range, a stiffer spring is needed to get the open pressure up where it needs to be. High lift kits are designed to have the correct open pressures at high lifts, this kit is designed to produce suitable open pressures at low to mid lifts.


This kit, part # VSK7E48-M is from our "Max Output" family.

As with our other GT40 kits, this one fits the stock valve tip lengths used in this application. (.393"/.481")

Fits GT40 heads without additional modifications; machine work is not required. Just set up the installed heights, assemble and go..


      Spring Specifications: (Average)

  • Spring Type- Heavy Duty Single w/ Damper
  • Machine work required?- NO
  • 1.480" Outside Diameter- fits factory castings
  • I.D.- Fits over stock 1.00" register step
  • 126 Lbs @ 1.765" Valve Closed Installed Height
  • 276 Lbs @ .440" Lift
  • 291 Lbs @ .480" Lift
  • 300 Lbs @ .500" Lift
  • 308 Lbs @ .520" Lift



     Kit includes:

  • Package of eight intake retainers & locks, labeled for easy identification
  • Package of eight exhaust retainers & locks, labeled for easy identification
  • 16 Drop in performance springs
  • Specification sheet
  • Installed height diagram w/ target installed height- Use installed height specifications included with your kit.



Requirements: As with any aftermarket performance spring kit, proper installation requires measuring the installed heights and adding shims as needed to obtain the target installed height as shown on the spec card included with your specific kit.

Buyers can order shims and or or seals by checking the boxes at the right of the pictures at the top of the page. These items are added in at slightly discounted prices with reduced shipping rates.

Note the Viton seals we now carry are absolute best SB Ford seals available on the planet. They have a ribbed ID which improves ease of installation and seals better around the guide ID. Don't use cheap gasket set seals for your street machine, get the best from Alex's Parts.


Alex's Parts- The smart choice in valve train parts~

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