906 head guide post

[Ray70Chrg]

In the middle of cam, lifters, spring, the works replacement. Heads still on engine. Putting in a Lunati voodoo 703 cam and their recommended springs which are double and damper. The inner spring has inside diameter of .75 in. I've searched all the postings here and looked in everywhere else for stem seals that will fit inside the inner spring and around the original guide. The service manual makes no reference to the outside dimension of the valve stem guide. This is a 906 head. Has anyone been able to find seals that meet these requirements. Thank you in advance for helping. Also, does anyone know the outside diameter of the original guide post.

 

[yella71]

Im thinking there is no seal for what you want as the OE guide is is very large if uncut in that area. I don't even think you can put double springs on that head without at least cutting the spring pocket. They are usually cut to .500 to accept a seal on the guide. The reason the service manual does not give a spec is stock heads use umbrella seals that do not go over the guide. They ride on the valve stem.

 

[wyrmrider]

thereis a thread on single springs that work do a search
coon problem
any beehives that will fit ootb?
how was your timing chain?
some have machined the seats and guides in the car by plugging the drain holes and pushrod holes and using a couple of vacs while cutting...

 

[PRHeads]

The guides would get cut for seals, and shortened as required for the lift of the new cam at the same time the spring pockets are being cut for the dual springs.

I’m sure there are several people who have used the Lunati 703 cam with the springs that come on Edelbrock heads....... which are singles.

 

[khryslerkid]

Had to do mine for different springs. A good machine shop can do them or do them yourself with a couple of tools.

https://www.forbbodiesonly.com/moparforum/showcase/reworking-452-heads-for-new-springs.4648/

https://www.forbbodiesonly.com/mopa...-452-heads-for-new-valve-springs-part-2.4657/

 

[PRHeads]

Had to do mine for different springs. A good machine shop can do them or do them yourself with a couple of tools.

https://www.forbbodiesonly.com/moparforum/showcase/reworking-452-heads-for-new-springs.4648/

https://www.forbbodiesonly.com/mopa...-452-heads-for-new-valve-springs-part-2.4657/

Great little tutorial there

That’s exactly how it should be done.

 

[Ray70Chrg]

Thanks to everyone for their input. Cutting those posts is well beyond my capabilities. I do admire the skill and knowledge it takes to complete that task. Plan B for me is I'll get a set of single spring w/ damper that is very close to strength of the springs I can't use. Also, in order to properly break-in the cam I'm going to use the original oem springs which were rated very close to the main spring of the combo. Lunati says to use only the main spring, not the combo, to break-in the cam. Somewhere down the road I'll be considering a change to aftermarket heads so that's another reason I don't want to get too involved with the 906s. Does anyone think plan B is not good?

 

[beanhead]

I don't see why that cam would necessarily need a dual, but then again it might be nice if Lunati put specs and recommendations on their website. I guess they want you to call their tech line even for basic info--lame. A good stout single w/damper would work, if you found one that fit and had the proper force, but pay close attention to the installed height spec. Don't wanna run into clearance problems with the umbrella seals.