'66 L72 cast date and AO Smith body date

[Allen Murray]

I am restoring a '66 AO Smith convertible. The body assembly date is I27, serial #121199. This car has has all the signs of an original big block. I also have a '66 L72 engine that I am putting in it. The cast date on the block is E 3 6. Even though it is not the original motor, would the casting date be correct for judging? I would like to make the car as original as possible. Thanks.

[Rob M.]

Re: '66 L72 cast date and AO Smith body date

Allen,

I have a 66 AO Smith SB with a body build of I26, serial #21064. The block has a cast date of D 7 6 and assembly date of 0427. I think that your block cast date is too tight to work for your car as far as judging is concerned. Even if the block was cast and assembled within a 24-36 hour window (which happened, but was rare), I doubt that it would have made into your car before it was off the line which I think would have been May 6th. But, what do I know it may be considered to be fine by the more experienced members/judges.

Good luck,
Rob

[John H.]

Re: '66 L72 cast date and AO Smith body date

The casting date (May 3rd) was a Tuesday, so it's unlikely it would have been machined/assembled before the 4th or 5th (Wednesday/Thursday), and that wouldn't have left enough transit time to get it on a train, then from the Tonawanda marshalling yard to St. Louis, unloaded, and to the engine dress line by Thursday night or Friday morning.

[Allen Murray]

Re: '66 L72 cast date and AO Smith body date

Thanks for the replies guys. Am I correct in assuming that based on the serial # you have determined that my car was assembled on the 5th or 6th of May? What does the I27 date on the trim tag refer to? I have been reading Noland Adams book, but I'm still confused. On page 39 it says that is possible to have a AO Smith body build date which is prior to the engine casting date.

So in essance, based on the serial #, it is not likely that the engine was cast only 3 days prior to assembly of the car when the serial # was attached. Am I following this correctly?

[John H.]

Re: '66 L72 cast date and AO Smith body date

Allen -

The "I27" date on the trim tag says the body was built at A.O. Smith on April 27th, and the "Birthday Book" estimates that the car came off the line at St. Louis on Friday, May 6th. It's possible to have a block cast after the A.O. Smith body build date, but a May 3rd casting date is too late for a May 6th final-assembled car.

[Allen Murray]

Re: '66 L72 cast date and AO Smith body date

Thanks for the info John. What is the minimum acceptable number of days from block casting to "birthdate" of the car? I have heard up to 6 month prior, but never heard how few days is possible.

[Rob M.]

Re: '66 L72 cast date and AO Smith body date

Allen,

I would say the block would have to have been cast the last week of April, around the 25th or 26th and assembled within a day or two of that to have made your car (and that is cutting it very very close). A better date would be a casting of early/mid April and an assembly date in late April.

My car was built only one day ahead of yours, and the only part that I have found dated in May was the starter - May 2nd. Almost everything else is dated sometime in April - from the carpet to the 3:08 rear end.

Regards,
Rob

[Jerry M.]

Re: '66 L72 cast date and AO Smith body date

Allen,

These are some true sequences on my 66's.

St. Louis body 7/29. Cast date 6/17. T stamp 6/27. Assembly 7/30 + -
AO body 2/24. Cast date 2/16. T stamp 3/1. Assembly 3/6 + -
AO body 1/12 Cast date 1/14 T stamp 1/17. Assembly 1/22 + -

Seems there is quite a lot of variation. Maybe busiest time of year means something. Who knows? Hope this helps.