gtfoxy

I just picked up a 04 GTO that has a set of heads that I cant seem to identify.

The tab numbers are not there & the only numbers under the cover is "C306" & a "7". Also, on the sides under where the casting numbers usually are, there is a loing series of numbers starting with "609". See pics.

If anyone could tell me what these are I would be greatly appreciative!

Paul Bell

iTrader: (9)

Assuming these are the original heads on this engine, they should be the 2000~2004 LS1 heads number 12564241.

gtfoxy

That's what they are supposed to be but, with no numbers on the heads I can see I can't assume they are. I'll yank the intake tomorrow & see what is under there for part numbers.

I know companies like Patriot will mill the tab & put their own serial # on them so I didn't know if this was maybe a set of ported heads from someone.

DietCoke

iTrader: (18)

pull the manifold off and look at the exhaust port, will tell you what kind of head it is

redtan

iTrader: (5)

Well those don't look like the stock rockers, unless 04s had different ones than later years.

I'd venture to say those aren't the original heads, or they have at least been taken off. Be curious to see what the ports looked like.

1989GTA

That is correct, those are not the stock rocker arms or exhaust. So no telling what has been done to the car. As stated those are probably not the stock heads. Maybe they are CNC'd and they were exchanged with the stock ones.

gtfoxy

No they aren't stock, for sure.

I picked this up from a guy that didn't build it up but it apparently has a LS9 cam & a LS6 intake so the heads have to be from that vintage. KCS suggested Comps & he is probably right.

Not sure what the bottom end is either. Story gets sketchy when, while selling it, he said a guy contacted him that knows the guy that he bought it from & told him it has either a stroker kit in it, or an LS2, he wasn't sure but assured him it wasn't a stock LS1. It even has a boost gauge on it so it was forced induction at some point. & it also has LS2 style injectors.

It's karma, now I almost have to put some boost to it. Seeing that gauge only going to "0" really depresses me...

1989GTA

When I had my L92 heads CNC'd by Texas Speed the factory numbers went bye-bye and were over written by Texas Speed.

gtfoxy

I see a few companies doing that, hence the reason I mentioned it.

I'll do some more investigating & see what I find out.

gtfoxy

Still don't know exactly what they are, yet. But I know for sure they are ported & CNC from the cutting marks.

Headers will be off soon & I can yank the heads.