How does one I.D. early GN 1 Heads?

[jjvites]

I was curious if someone can tell me how to tell the early GN 1 heads from the late model ones? Are there date codes on them or do they look a little different?

Thanks,
jjvites

 

[jjvites]

Any help would be appreciated.

jjvites

 

[pwrhws]

Early ones are usually broken and repaired

If repaired check for welding arond the boltholes under the valve cover are at both ends of the head

 

[jjvites]

Thanks Mike. But if they are low mileage and maybe never yet cracked (as the ones I'm looking at) how would i know if they are early or late . The current owner never used them and doesn't know . If repaired are those O.K. at that point or are they like the driver side exhaust? (weld and weld again)

Thanks,
jj

 

[CPAKCP]

Originally posted by jjvites
I was curious if someone can tell me how to tell the early GN 1 heads from the late model ones? Are there date codes on them or do they look a little different?

Thanks,
jjvites

I got the following from another board member, hope it helps:

The Version 4 heads on the car were NEW from Champion. They have all the current casting revisions including additional material in the outside wall where they like to crack and the logo is now on the end of the head rather than on the side eliminating a stress riser in a critical area of the head.

Good Luck

 

[jjvites]

how many bolt holes 8 or 11? or ?

Thanks James, all info is appreciated.
As a side note, what do you guys think would be the next turbo ( currently using TA 49 with home ported heads) to take advantage of these heads. They are stock unported.
I was told these are the 8 bolt for 109 blocks , yet in the pictures there are an additional three holes, a total of 11. Are these heads made to fit both stock and stage blocks?

 

[V6 Beast]

Re: how many bolt holes 8 or 11? or ?

Originally posted by jjvites
Thanks James, all info is appreciated.
As a side note, what do you guys think would be the next turbo ( currently using TA 49 with home ported heads) to take advantage of these heads. They are stock unported.
I was told these are the 8 bolt for 109 blocks , yet in the pictures there are an additional three holes, a total of 11. Are these heads made to fit both stock and stage blocks?

I wouldn't think you would see any big advantage until you got to at least a 70 Turbo and supporting combo. Lot's of guys run irons well into the 10's including myself.

Sully

 

[750H.P.V6]

There are 4 versions that I know of. All four castings are available in etiher 8 or 14 bolt configurations. The 8 bolt heads actually have 11 bolt holes 3 of which aren't used unless you get a set of head clamps from RJC.

The first 2 versions of the heads of the heads are so similar that they could be considerer the same. The difference between these and the 3rd version is that the 3rd version has a thicker deck surface and actually takes longer bolts if you have a Stage II motor. The 4th version have the logo on the end of the head.

FWIW, I live down in San Diego and I'd be glad to check them out for you if the current owner is OK with that. Ask him how old they are as this might shed some light on which version they are too. BTW, I agree with what Sully just stated as good ported iron heads have proven to be less problematic than the GN 1's.

Neal

 

[10SV6]

Why don't you give Tom at Champion a call and ask him ?

 

[jjvites]

Neil, Sully, 10SV6,
Thank you for your response, Looking at your signatures I respect your accomplishments.
Buying the aluminum heads might not be all that cost effective for the performance gain. I guess we all hope to find a less painful way to get to the next level. Some times the gains come easier but a lot of the time its a battle with KR's, computers, chips, etc.
I did speak to Tom a while back and he was very nice. The cost of ported heads by him is similar to the cost of the used aluminum heads.