vin # and production date

[yellow12bolt]

where do you find the production date for a range of vins for a 65 chevelle. My body tag shows 5 C, and the 12 bolt rear end is CW 0 6 11 B. The rear end translates to 327 w/ air (and that is what the car is). The build card I found in it from fisher body also confirms the air and the vin is a V8, with body build date in late may. Was my car stuck in pergatory waiting for a 327 with 'air' coded rear end? Would the vin be the best clue on when the complete car was built? -bob

[yellow12bolt]

to add, what is a '327 w/ air' rear end code supposed to mean. I totally understand the metallic brakes and posi relevance in coding of rear end descriptions, but what about a '327 w/ air' is different than a 396 or 283 car? What does air conditioning have to do with a rear end?

[Don_Lightfoot]

In a lot of cases, maybe not all, the standard rear end ratio for a car with A/C is lower numerically than the same drivetrain without A/C. For example, a certain car without A/C might have a standard rear axle ratio of 3.31, whereas the same car with A/C might have a standard ratio of 3.08. I guess the car with A/C works a little harder than without A/C so the idea is to keep rpm's lower.

At least that's what seems to be in my mind

[DaleM]

where do you find the production date for a range of vins for a 65 chevelle. My body tag shows 5 C, and the 12 bolt rear end is CW 0 6 11 B. The rear end translates to 327 w/ air (and that is what the car is). The build card I found in it from fisher body also confirms the air and the vin is a V8, with body build date in late may. Was my car stuck in pergatory waiting for a 327 with 'air' coded rear end? Would the vin be the best clue on when the complete car was built? -bob

The sequence numbers reported by GM for each plant are on page http://chevellestuff.net/1965/plant_prod_no.htm. Be aware though these 'reported' numbers aren't 100% accurate. A car, or range of cars, could have been held up for some reason. There also does not appear to be a 'standard' as to when production numbers were reported. Did each plant write down the last car out the door at the end of a given shift and the end of the month? Probably not. Did GM report the last sequence number for a month based on a projected or average daily production? Probably closer to truth. I have several occurances of sequence numbers higher for a given month based on the body date.

And, to go along with the above, the body date is when the body itself was being built. Bodies could sit in the body bank at Fisher for any number of reasons for any number of days. Customer ordered cars would also get priority over, for lack of a better term, dealer stock cars. So bodies could already be built by Fisher and stored in the body bank until needed or until all the parts for a customer ordered car were available and this would account for drive line components dated later than the body date and the VIN sequence being much later than the body date. Normally cars didn't sit in the body bank that long but there were always exceptions.

to add, what is a '327 w/ air' rear end code supposed to mean. I totally understand the metallic brakes and posi relevance in coding of rear end descriptions, but what about a '327 w/ air' is different than a 396 or 283 car? What does air conditioning have to do with a rear end?

Sadly a lot of GM documentation isn't consistent with some of their descriptions. The CW coded 3.31 rear for 65 is just how it's listed for some reason. I can only surmise that the non-metallic brake, non-Positraction (or combinations of the two) two 3.31 gear sets were available, one labeled "Heavy Duty" (GA) and one labeled "327 w/Air Conditioning."

At least for 1966/1967 as I don't have a power teams chart for 65 where A/C and non-A/C is shown, only "General Purpose Standard" and "Special Purpose or Mountain". Where a small block in 1966/1967 with an automatic transmission might have a 3.08 standard gear w/o A/C, the same car with A/C would have a 3.36. I would guess the reasoning is it takes more 'umph' to get going with the A/C on so a numerically higher, but ratio lower, gear was the norm. On big block cars it seems to be the other way around. Where a 3.07 would be the norm on an automatic A/C car, 3.31 would be standard for a non-A/C car. Why? But they pay engineers big bucks to figure out what's typically needed.

[yellow12bolt]

thanks so much for the help. I am good on the rear end info. Makes total sense.
But I have to wonder about the date on the rear end. The car has a 159--- VIN sequence and is a baltimore car. The body shows 5C. The table on chevellestuff shows the VIN as corresponding to may 65. So is my rear end of cast date E 28 5 and axle tube stamp CW 06 11 B (june 11) too far off?
Do the assign a VIN before a car is completed? If so, my rear end if wrong.
Kinda bummed, thought it was the original 12 bolt to the car.

[DaleM]

Like I noted, it's still possible. Bodies were dated and built on the Fisher Body side of the plant and went to a 'body bank' where they may be held until that particular combination was called for. You say the VIN sequence is also for May...the VIN was assigned when final production began on the assembly side and all parts were on hand to build the car. In this case I would doubt the rear end is original to the car since the rear end is dated a couple of weeks after the car came off the assembly line.