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Stainless Steel Valves, SB Ford, GT40P Exhaust, Select 1.450" or 1.460" X .393" Tip, Set of eight

  • Select from 1.450" or 1.460" Valves
GT40P-393 or Gt40P-393-A
Calculated at checkout

Product Description

New Items # GT40p-393 or Gt40p-393-A
Stainless Steel Exhaust Valves for GT40P & E7
SB Ford GT40P w/ .393" Tip Length
Purchase is for eight exhaust valves.
Select between two versions: 1.450" or 1.460"


These Stainless Steel valves were custom made to our specifications. We produced them with a .393" tip length instead of the stock tip length of .481".
If you're ordering a spring kit from us, we can provide the parts to fit either .393"/.481" or .393"/.393"
When ordering a spring kit at the same time as the valves, we'll provide the spring kit to match the valves purchased.
If you already have one of our spring kits for .393"/.481" tip length valves, the fix is to change the locks on the exhaust to the same type used on the intake. If you need help ordering the correct locks, simply message us and we'll send you a link to them.
GT40P-393 is used to replace the stock valve. It's head diameter, face width and overall length replaces the stock exhaust valve very well and is intended for the "do it yourself-er" who is familiar with lapping valves. This valve uses the stock head diameter of 1.450" and has a wide enough face to contact the factory machined exhaust seat. If you try to use the 1.460" exhaust valve on the factory machined seats, the seat contact surface would most likely be partially hanging off the bottom edge of the valve face due to it's narrower face width and .010" bigger head diameter.
Please note that lapping new valves into used seats only works when the used seats are still in very good condition. Some heads will have worn out seats which lapping alone might not offer a suitable service life. If the used exhaust seats show allot of wear, they should be machined as is done during a valve job. The 1.450" valve can still be used for heads getting a valve job also but will not have the same flow advantages as heads specifically machined for the 1.460" valve.
For those who will be taking their heads to a machine shop, they'll want to order GT40p-393-A (1.460") This valve has a slightly bigger head diameter and a special narrow contact face width which the machinist would cut or grind the exhaust seat to match. This offers improved flow over a wide valve face. The improvements are similar to wide face valves which have been "back cut" to a narrower width. Since the 1.460" valve is manufactured with a narrow face, back cutting is not possible as it already has the desired narrow face width.
  1. Order GT40p-393 for those changing exhaust valves without machining the exhaust seats.
  2. Order GT40P-393-A for heads going to the machine shop for a valve job. Your machinist will machine the new exhaust seats to fit this valve.
Be sure to give the machine shop the valves so they can machine the seats to your valves. Anyone doing precision machine work knows they need the valves in hand to set up the proper seat widths and locations.
Select the valve which suites your needs best by checking the appropriate check box towards the top of the page.
      Features: both Gt40P-393 or Gt40P-393-A
  • Premium Stainless Steel material
  • 21-4N Material
  • Undercut Stems
  • Swirl Polished
  • Solution Heat Treated & Age Hardened
  • Hard Chrome Stems
  • Tulip Head for lower weight and improved flow
  • Hard Tips
  • Fully CNC machined
     Sizes: GT40P-393
  • 1.450" Head Diameter
  • 5.070" Overall length
  • Stem Diameter- 11/32"
  • Groove Configuration- Square, stock shape
  • .393" Tip Length
  • Use in heads which will replace stock exhaust valves.
  • This version takes around 10 days to ship after ordering.



     Sizes: GT40P-393-A
  • 1.460" Head Diameter
  • 5.070" Overall length
  • Stem Diameter- 11/32"
  • Groove Configuration- Square, stock shape
  • .393" Tip Length
  • Use in heads which will have their heads valve jobbed at a machine shop. They will machine the seats to work with the increased flow design of Gt40p-393A valves.
  • This version is in stock and ready to ship.


Matching intakes sell under part number Gt40i
This valve also fits early SB Ford 302 starting in 69 as the older 302 & 351W engines used 1.450" or 1.460" valves w/ .393" tip lengths.
NOTE: GT40P-393 valves take around 10 days to ship after ordering.

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