Cylinder head date code

[Peter S.]

I will not taint the jury. What do you see?

[Steven B.]

Re: Cylinder head date code

Late for my eyes but the "9's" look cast backwards

[Michael D.]

Re: Cylinder head date code

Date code looks like E or F 18 8 to me.

[Michael W.]

Re: Cylinder head date code

E or F
13,16 or 18
8 or 9

[Alan S.]

Re: Cylinder head date code

Hi Peter,
My first thought was F 18 8.
When I enlarged it I thought F 13 8.
Regards,
Alan

[Peter S.]

Re: Cylinder head date code

Well, it's clear that I am not the only one with issues reading it! It also appears that the "6" in the casting number is upside-down.

This is a 5-point decision as this is my driver's side cylinder head. How about a close-up?

Alan, you really think that final digit is an 8?

[Michael W.]

Re: Cylinder head date code

This is a 5-point decision

What does this mean?

[Michael D.]

Re: Cylinder head date code

I'm lost. Your question concerned the casting date. The final 6 looks upside down in the casting number.

[Peter S.]

Re: Cylinder head date code

I'm lost. Your question concerned the casting date. The final 6 looks upside down in the casting number.

Sorry Michael, didn't mean to confuse. I was just noting the funky casting number. My question concerns the casting date. I have a September 13th, 1969 build date, a 1968 cylinder head would not work.

Was the 186 even cast in June/July of '68 for the '69 model for assembly in September of 1968? If my research is correct, the '68 models used the 291/292 heads and 1969 was the first year of the 186.

[Alan S.]

[Peter S.]

Re: Cylinder head date code

Alan, I think I am sold on F 13 9. I agree with your analysis, and perusing ebay listings for '68 castings and '69 castings, it is clear it is NOT an "8". Thanks for your opinions.

[Peter S.]

Re: Cylinder head date code

What does this mean?

Hi Mike,

The NCRS employs a point system based off of originality and condition. The judging system allows a total of 50 originality points for cylinder heads for '68-'72 model years. Applying CDCIF, If this is a 1968 cylinder head, then my date code is well outside the acceptable 6 month span. Taking 20% for incorrect date for 1 cylinder head, this math gets me to 5 points.

I am sure you are more than familiar with the judging breakdown, I am spelling out my train of thought since you asked.

[Harry S.]

Re: Cylinder head date code

I've never asked an owner to pull a valve cover, thus zero deduct if the visible characteristics are correct.

[Patrick B.]

Re: Cylinder head date code

The 3927186 heads were produced for 1969 model year cars, but it would not be impossible for the first castings to have appeared in June of 68. However, your enlarged picture looks more like a 9 than an 8.


A potential problem may be that these are 3927188 heads rather then 3927186 heads. The 3927188 heads were for low compression 327's still in use in full size Chevys in 1969. They used a smaller intake valve (1.72 rather than 1.94) and also had a much larger chamber volume. They did not use the rounded double hump casting symbol on the end of the head like the 186 heads. (They used two vertical bars instead.) If these heads do not have the double hump casting symbol does not use them.

[Michael W.]

Re: Cylinder head date code

Hi Mike,

The NCRS employs a point system based off of originality and condition. The judging system allows a total of 50 originality points for cylinder heads for '68-'72 model years. Applying CDCIF, If this is a 1968 cylinder head, then my date code is well outside the acceptable 6 month span. Taking 20% for incorrect date for 1 cylinder head, this math gets me to 5 points.

I am sure you are more than familiar with the judging breakdown, I am spelling out my train of thought since you asked.

Cylinder head casting numbers and dates are not judged.