skipinhouston

Where are the casting number locations for cylinder heads and how do you identify what they are?
I have been told I have "camel" hump heads. What are the identifying marks for that?
I've also been told that smog heads have "D" shaped ports..... intake or exhaust?
Mine do not have "D" shaped anything.
Thanks again in advance.
I know you guys have the answers.
Skip in Houston

ToplessLS3

The casting numbers and dates are in the heads under the valve covers.

MorTec.com has a complete listing of the correct head numbers for your car.

What year is your car?

skipinhouston

I have a '73 but my buddy has a 1980 and has been told that he needs different heads.
Yes, my head have had new hardened valve seats installed.
Thanks for the reply.
Skip

Tom73

The '73 had those from the factory, the first year to have them, getting ready for the upcoming unleaded fuel.

Easy Mike

On the end of the head. http://www.geocities.com/meanracing/...ngNumbers.html

jaki30

I believe the change to hardened seats happened in the 1971 models.
That is why they dropped the compression ratio on most of the engines.

Mike Ward

Partly correct, the hardened seats came about in '71 but this had no connection to the lowered compression ratios. That was more to address pollution regulations of the day with current technology low cost solutions.

It's ironic that the need for the hardened seats was eventually proven to be redundant in Corvettes, but I guess since the heads were mass produced and could end up on any car or truck it would not be cost efficient to divert some of the heads destined for light duty applications.

Water under the bridge now.............

gerry72

Hardened seats came out in '71. The same time low-lead (the precursor to no-lead, unleaded, and now just pump gas) was introduced. GM was induction-hardening the seats. The seat treatment had nothing to do with compression, though compression reduction was a consequence of the low-lead fuel since the octane rating went away with TEL.