[Early 64 build date mystery]

Fred,

Interesting. So the stamp format on your car is all numbers. My date stamp is AUG 20 1963, with the month abbreviation in all caps. I am surprised that they were using two different kinds of stamps over such a relatively short period of time, but obviously they were. Hopefully there are some other examples out there that might shed more light on this. It's certainly puzzling and we may never know why they did things with so much variations. Thanks for the information.

Dave

[Early 64 build date mystery]

Fred

On your build sheet, is your build date written in the box label "Final Assy. Date" or is it a stamp with the Month abbreviated, the day, and then a 4 digit year. The date code for your engine is also after the build date, so given the inspection sheet, I think the most likely explanation is that they wrote/stamped the wrong build date - i.e. Sept 4, 1963 should have been Sept 14, 1963. If written, it could be a human error. If the stamp date is wrong, it would be very easy for the "1" to disappear if they were using settable stamps, and the setting wheel got bumped a little. While I'm new to Avanti's, I've seen a lot of factory errors from the 50's and 60's on paperwork, and other anomalies that have popped up over the years. At the time, the car companies were much more concerned with getting product out the door, and not that fussy about "minor" issues or variations.

[Early 64 build date mystery]

Fred,

Thank you for the additional information. It certainly matches what I would have expected for an engine built on Sept 9, 1963, but then you state that your car was "built" on Sept 4th, which leaves me puzzled. I wonder if there is a difference between "built" and "completed"? For my car, the factory inspection sheets are dated 8/12/1963 for the body, and the chassis sheets are dated 8//14/1963. My build sheet is stamped August 20, 1963, which I assumed was the official build/completed date, but perhaps the built date is assigned before the car is actually completed? I'm sure that when the factory was doing all of these things in 1963, it never occurred to anyone that 52 years later, anyone would be looking that closely! With a matching build sheet and engine block, you know yours is original, so it's hard to say why the "build" date was listed as Sept 4, unless then meant to set it to Sept 14th??????

Dave

[Stan Gundrys Book]

I also mailed a check and got the book yesterday. Quick service and well worth the cost. The book quickly answered several questions I had about my Avanti that were not covered in the service manual.

[Early 64 build date mystery]

Skip

Do you know if they used 3 digits or 2 digits dates for Avanti engines built in early Sept 1963. For example, would an engine built on Sept 9, 1963 have been stamped RJ39 or RJ309? Obviously once it was the 10th of the month, it automatically had to be 3 digits.

Dave

[Early 64 build date mystery]

Thank you for the update. It confirms that the new number format was indeed in use prior to August 20, so I think it is fairly safe to assume that the note about the number change on August 20 was indeed only referring to using a 3 digit date code from that point on instead of just 2 digits for single digit months. So that an engine built on Sept 9. 1963 would now be RJ309 instead of RJ39 as it would have been if they hadn't changed the date format on August 20, 1963.

[Stan Gundrys Book]

I would also like to order this book. The link on the web page is now a gmail address, but I haven't gotten a response when I sent an email asking to confirm the mailing address as a P.O. Box in Grand Rapids, MI. I don't want to send a check if the information is old. Does anyone know if he is still selling the book and still in Grand Rapids?

Thanks

[Early 64 build date mystery]

That is very helpful as it decodes that your engine was built on August 1, 1963. That confirms that this engine number format was used as of August 1. The only real question now is if any engines from July used this format, or was the format change to a date code from a serial number done for all Avanti engines built on or after August 1, 1963.

[Early 64 build date mystery]

Update

I found another 1964 Avanti that has a completed date of August 16, 1963 and has engine RSH37. It is R4670 which is an R2, and the RSH37 decodes that the engine was built August 7, 1963. My R1 car R4959 has engine RH36, which decodes to August 6, 1963. So the implication is that the new engine number system was being used prior to August 20, 1963. Perhaps as of August 20, 1963, the convention switched to the 3 digit date, so that an engine built on Sept 9. 1963 would have been RJ309. So perhaps the August 20th "change" was not the change of no longer doing a serial number for the engine, but simply a notification that in the future all would have 3 digits after the month letter????

Does anyone else have a car with the 2 digit date code from August 1963?

[63 on Ebay.What's it Worth?]

Do you have the link to Bob's eBay results for 2014 and 2015?

[Early 64 build date mystery]

I have a 1964 Avanti R4959 that has engine number RH36. This is the original engine, and the number matches the build sheet. Some of the references I am finding say that this engine number format was first used on August 20, 1963 for Avanti’s built on or after that date. My build sheet is stamped August 20 1963, so is that the official “built date”? The factory inspection sheets are dated 8/12/1963 body and 8/14/1963 chassis. The car was invoiced 8/23/1963 showing R Q 4370 Avanti in P 6431 Avanti White. Body number is RQ 3873 which also matches the build sheet. Would inspections have normally started before the engine number was stamped? This is a round headlight car.