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Valve Spring Kit GT40, Low & Mid Lift Cams, High Output 1 Drop in up to .540" Lift

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Calculated at checkout

Product Description

Fits Factory Heads, no machining required.

Drop in Spring kit for: Mid Lift Cams. (.480"-.540")

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 of our popular GT40 valve spring kit is intended for mid lift cams.

When used with a mid lift cam, this kit provides more open pressure than if a high lift spring kit is used.

If your cam and rocker ratio combo produce between .480"-.540" lift at the valve and duration is no more than 236 degrees @ .050", this kit is a good selection.

When running low to mid lifts, a stiffer spring is needed to get the open pressure up where it needs to be. High lift kits are designed to have the desired open pressures at high lifts, this kit is designed to produce higher open pressures at lower lifts.

This kit, part # VSK7G48-M is from our "Max Output" family, it's a mid lift, high output spring.

As with our other GT40 kits, this one fits the stock GT40 valve tip length configuration.

Comes with Springs, Chrome Moly steel retainers and hardened locks. Parts are marked for Intake and Exhaust positions.

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


      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
  • 120 Lbs @ 1.780" Valve Closed Installed Height
  • 288 Lbs @ .480" Lift
  • 296 Lbs @ .500" Lift
  • 312 Lbs @ .540" 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 the 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 hot rod, get the best from Alex's Parts.


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

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