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GMC V6 and V12 Engines Engine repair and rebuilding

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  #11  
Old January 4th, 2020, 07:44 PM
bigblockv6 bigblockv6 is offline
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Default Re: Magnum Exhaust Valve Replacement

I checked out the auction on those exhaust valves, they are the stock hollow stem sodium filled valves, definitely a weak link as they can snap for over revving. I bought some Cat valves a while back that are the same diameter but with smaller diameter solid stems, only issue is the stems are shorter so I don't think they can be used. I intend to replace the hollow stem valves on my 478M in the future, knowing myself being a lead foot. and the fact my 478M was built up to rev over stock specs!
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  #12  
Old January 4th, 2020, 08:30 PM
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Quigley Quigley is offline
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Default Re: Magnum Exhaust Valve Replacement

Here's what I did. Used Trick Flow stainless valves for 429&460 Ford Trick Flow Heads. Part#TFS54503212 with 13160-8 10 degree keeper and 748-16 Retainer. The valves are.080in shorter than stock,which doesn't cause any problem with the spring and used a 11/16 lash cap on top to add length,part #621-16. Install Bronze valve guides part #VG-7006R . Adjust rockers for stock clearance. Hope this makes sense. Worked for me to get rid of the sodium fllled valves. Dave
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  #13  
Old January 4th, 2020, 08:43 PM
bigblockv6 bigblockv6 is offline
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Default Re: Magnum Exhaust Valve Replacement

Wonder if the 429/460 valves will work in my 478M because I'm using higher lift valve springs for the custom ground cam, ironically those higher lift valves springs fit Ford 390 applications.
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  #14  
Old January 5th, 2020, 05:35 AM
1972RedNeck 1972RedNeck is offline
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Default Re: Magnum Exhaust Valve Replacement

Quote:
Originally Posted by bigblockv6 View Post
Wonder if the 429/460 valves will work in my 478M because I'm using higher lift valve springs for the custom ground cam, ironically those higher lift valves springs fit Ford 390 applications.
Really? Just a set of performance FE valve springs? Good to know.
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