How close are the date codes of # matching engine parts normally? I have a 68 400 HO 4 Spd, with the correct #’s matching block and 16 heads with date codes of J137 and J167, I don’t have the 9790140 intake though, would that be within a few days also? I found one with a H227 code, but would that be to big of date gap to be “correct”?

More important in my mind is how does H227 relate to the build date of your vehicle? That code 9790140 went on a lot of V8s (350s and 400s, 428s) so they were being produced constantly.

Build date of car is 4th week of October?

Just wanted to bump this back up, find some 0140 intakes for this motor every so often but nothing with a J of 67 date, wondering just how close the dates on #'s matching original cars were to block/heads or build date of car?

How about the dates on a 1111449 distributor, need one of them also if I were to ever come along one.
And then there's the ole 7028271 carb I would need to complete it, but the few of them I've ever seen have been crazy high $$!!

Just curious as to how close the dates of these components were to the build date of car and engine/head stamps just incase I were to ever stroll by some of them?

. Reading the number letters on the casting.... looking at casting numbers The first letter is the month the second two numbers is the day and the last single number is the year.. then there is a casting that looks like a dotted circle with a pointer In the center this indicates day or night shift time....you just have to worry about the right date....examples....H227 h is October 22 is the 22nd day and 7 is 1967. ....A189. Is January 18 1969.. from what I understand it’s about 3 to 4 weeks before the build date of the car is a good guideline ..getting correct carbs aren’t cheap. I waited for 15 years to get the correct HO carb for mine.. it’s worth it to me...

My factory original intake is dated L057 on my 1/29/68 Bird. I suspect that means December 5, 1967 (about 7 weeks lead).

What is confusing for the end of year parts is some GM parts seem to use "I" for September and some skip it; meaning December is "L" for some parts (e.g. engine parts castings) and "M" is December for others (e.g. alternators).