1966 427/425 Head Casting Date

[Bob A.]

The Trim Tag on this 1966 is a G17, which I believe is March 17, 1966.
The VIN # is 194676S115077.
I would like to purchase a correct set of (3873858) Heads for this 1966 427/425.
What Casting dates should be on each Head?

Many Thanks for your HELP!

Regards,

Bob

[Joe L.]

Re: 1966 427/425 Head Casting Date

The Trim Tag on this 1966 is a G17, which I believe is March 17, 1966.
The VIN # is 194676S115077.
I would like to purchase a correct set of (3873858) Heads for this 1966 427/425.
What Casting dates should be on each Head?

Many Thanks for your HELP!

Regards,

Bob

Bob------


As far as NCRS and NCCB are concerned, I believe that any head that preceded the build date of the car by 6 months or less AND which also preceded the stamped build date of the engine would be considered correct.

Aside from the judging issue, it's hard to say what a "normal" cast time period a set of heads for your engine would be because big blocks have a lot more variability in this regard than small blocks.

As a practical matter, it's kind of moot because the casting date and casting number cannot usually be seen (unless one or the other happens to be visible through the oil filler opening on the right side of the engine).

[Bob A.]

Re: 1966 427/425 Head Casting Date

Joe:

I appreciate and understand you response. However, I am not familiar with the actual 427/425 Date Codes that would apply to a vehicle built in March of 1966. For example: F220 & E266, what do they mean? Also, what codes would fall within your criteria for this vehicle?

Regards,

Bob

[Joe L.]

Re: 1966 427/425 Head Casting Date

Joe:

I appreciate and understand you response. However, I am not familiar with the actual 427/425 Date Codes that would apply to a vehicle built in March of 1966. For example: F220 & E266, what do they mean? Also, what codes would fall within your criteria for this vehicle?

Regards,

Bob

Bob------


The alpha character system for castings is different from the alpha character system for body build. Body build coding begins with "A" representing whatever month that production for a model year begins and increases by one letter of the alphabet for each subsequent month.

Castings are usually dated with the alpha character "A" representing January, "B" representing February and so on. The letter "I" is usually used for casting dates and represents the 9th month of the year, September.

In your case, you would want heads no earlier than October 18, 1965 (represented as "K 18 5" or "K 18 65" if a two digit year is used). You would want them dated no later than a day, or so, before the build date of your engine. This is found on the stamp pad represented by the 4 digits following the "T". For example, 0304 would represent March, 4. No reference to year is provided in the stamping. One has to obtain that from the casting date.

For your casting date examples "F220" would decode to June 22 of 1960, 1970, 1980. For a head like the 3873858, none of these would be possible since the head was not being produced in 1960 and was out-of-production well before 1970.

The "E266" date would represent May 26, 1956, 1966, 1976, etc. For a 3873858 the only year the "6" could represent would be 1966 since the head was not in production in 1956 and was out of production long before 1976.

[Bob A.]

Re: 1966 427/425 Head Casting Date

Joe:

Upon closer examination, due to your response, I discovered that the actual Casting Codes are E266 and F226. Therefore, these codes would represent May 26, 1966 and June 22, 1966 and would not be correct for a 1966 Corvette with a G17 on the Trim Tag and a 115077 Production Number. Many Thanks for your detailed explanation. Your HELP in GREATLY APPRECIATED!

Regards,

Bob

[Jack H.]

Re: 1966 427/425 Head Casting Date

Bob------


The alpha character system for castings is different from the alpha character system for body build. Body build coding begins with "A" representing whatever month that production for a model year begins and increases by one letter of the alphabet for each subsequent month.

Castings are usually dated with the alpha character "A" representing January, "B" representing February and so on. The letter "I" is usually used for casting dates and represents the 9th month of the year, September.

In your case, you would want heads no earlier than October 18, 1965 (represented as "K 18 5" or "K 18 65" if a two digit year is used). You would want them dated no later than a day, or so, before the build date of your engine. This is found on the stamp pad represented by the 4 digits following the "T". For example, 0304 would represent March, 4. No reference to year is provided in the stamping. One has to obtain that from the casting date.

For your casting date examples "F220" would decode to June 22 of 1960, 1970, 1980. For a head like the 3873858, none of these would be possible since the head was not being produced in 1960 and was out-of-production well before 1970.

The "E266" date would represent May 26, 1956, 1966, 1976, etc. For a 3873858 the only year the "6" could represent would be 1966 since the head was not in production in 1956 and was out of production long before 1976.

Just to clarify, in midyears I thought the "I" was not skipped for engine and head casting dates, i.e. K would be November, not October....correct? Just trying to do a reality/sanity check.

[Joe L.]

Re: 1966 427/425 Head Casting Date

Just to clarify, in midyears I thought the "I" was not skipped for engine and head casting dates, i.e. K would be November, not October....correct? Just trying to do a reality/sanity check.

Jack------


The "I" was not skipped in just about any casting dates. I just made a mistake; the "K" should be November.