I'm completely confused by this. I went to AutoZone today and was poking around in their computer to see what kind of heads they offered for replacement when the computer asked me if I was looking for a 6 or 7 exhaust bolt hole head. Actually it didn't say bolt, but i found a head on the Mortec that says bolt. Anyhow... What's the difference???

 

my aluminum L98 heads have eight holes for the exhaust but there's a ninth right before the first hole at the front of the head that's not being used. Goes like this:
X=spare hole, O=exhaust hole

<-front X O O O O O O O O

i know this is a v8 but maybe your v6 has the same extra hole in front

 

V6????? No way in H E double hockey sticks, bro. LOL Check out casting number 376450 on http://www.mortec.com/castnum.htm. That's a V8 head. And I was checking out Corvette heads for my 350 and that's what it asked.

 

I've got Hooker Header that only have 6 holes, but most importantly my Edelbrock SBC-350 heads have 6.

X=header tube
0=Bolt hole

0X0 0X X0 0X0


I think the 7 hole is for a bracket on a stock manifolds or something...I know I've seen them before, I think it was for a AC braket?

Ron

 

If you are running headers either 6 or 7 bolt hole heads will work. If you are running late model exhaust manifolds you will need the 7 bolt hole heads.

Lonnie

 

woops i thought for some reason you said it was a v6, i dunno why

 

It's OK, dude. LOL Sorry if I came off sounding like an AH. LOL Aggrivating morning. Woke up REALLY early to go bring my 350 block down to the machine shop to get dipped, honed, and have new cam bearings and freeze plugs put in, but I ended up with no vehicle for a while to do it with.

So... The heads AutoBlown has have odd casting numbers that I can't find anywhere, and it looks like the manufacturer listed is Recon. <shrug> I'm figuring they're AutoZone reconditioned heads, but I don't know why the casting numbers wouldn't match anything.