What are the casting numbers for the Z06 heads?

Are they the same as the hd heads cast #317?

Anyone know the casting numbers and available valve sizes for all the heads available for the GTO.


I'd love to see some flow numbers.

If your asking if the GTO's heads are the LS6's then no they arn't. If they were people wouldnt be getting gains by putting LS6 heads on the GTO....which they are.

I knew that. :-)
I'm trying to find out if the Z06 has the 317 cast heads and what other casting numbers are out there and possibly the valve sizes.

The casting number is stamped right on the front of the pass side head in plain view the GTO heads are cast #241

The Chevrolet Express Vans,HD Trucks and Hummers with the 6.0 have cast #317
They have 71.06cc combustion chambers, 210cc intake ports, 75cc exhaust ports, 2.00 intake and 1.55 exhaust valves.

I'd like to have all the options before making any considerations.

Nocturn,
I saw some 317 cast for 500.00 new ready to bolt on.
That's why I wanted to know the Z06 casting number.

The heads and cam are my next project. I'm just getting my car back together from the little incident and hope to be on some mag wheels soon and then on to the engine compartement.

You have SI2000 access right?
I was thinking that I saw Nocturn on there too.?.?.?

I haven't had a chance to look for the casting numbers on SI. Are they listed?

Originally posted by ronhall512@Nov 30 2004, 07:13 PM
What are the casting numbers for the Z06 heads?

Are they the same as the hd heads cast #317?

Anyone know the casting numbers and available valve sizes for all the heads available for the GTO.


I'd love to see some flow numbers.
Z06/LS6 heads are cast #243. I believe the valves are 2.02/1.57 and they are sodium filled for reduced weight.

#317 cast heads are the 6.0L iron heads. They will give you a lower compression ratio if that is the desired effect wanted.

Here is a set of aluminum cast # 317 heads for sale on ebay for 300.00

Item number 7938739584

The 04 HD and the Express Vans we have at work have the same heads on them.

Holy smokes I found the 243 cast Z06 heads $1600.00 :o

That's a lot of :friday: money.