66 block stamping

[Jerry Weidner]

Can someone tell me what assembly stamp would be on a 66 427 block with a casting date of I-22-5.

Thank You,
Jerry

P.S
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[Joe L.]

Re: 66 block stamping

Jerry----

Welcome aboard.

I'm not sure exactly what you mean by "assembly stamp". However, if you are talking about the assembly or manufacturing code of the engine stamped on the engine pad, it will be a "T" followed by 3 or 4 digits representing the month and day. Uusally, these will be in the range of 1 week to 2 months after the block casting date, but up to 6 months is NCRS-acceptable (as long as it precedes the build date of the car the engine is in).

The last 2 characters of the stamping will be the "suffix code". This identifies the actual engine. Several codes were used for 1966 Corvette 427 engines and are as follows:

IK= L-72 with M-22 manual trans
IL= L-36 with manual trans
IM= L-36 with manual trans and K-19
IP= L-72
IQ= L-36 with Powerglide
IR= L-36 with Powerglide and K-19

[Jerry Weidner]

Re: 66 block stamping

Joe thank you for the response, Yes I do mean the assembly stamp on the front pad, I was looking for more of an exact date of assembly for an I-22-5 block, I know by searching the registrys of other years you can see a pattern as to the exact or close to assembly date of the block. The car I am looking at has a build date of oct.15th 65 so I guess I would like to know if anyone has any examples of assembly dates for a 427 block cast on I-22-5 going into a car assembled on Oct.15. Maybe I am searching for information that is not available if so please let me know as I am a novice.

Regards,
Jerry

[Joe L.]

Re: 66 block stamping

Jerry-----

There's absolutely no way to exactly correlate a block casting date with an engine assembly date. The engine assembly date could have been the same day the block was cast all the way to 4 or 5 month later. Normally, it fell within the range I mentioned.

I would say that a block cast on September 22 could have found its way into a Corvette assembled on October 15. It would have required an engine assembly date very shortly after the block casting date, but that's the norm rather than the exception.

[Jerry Weidner]

Re: 66 block stamping

Thanks again Joe maybe I was going about it the wrong way, Is there a correlation betwwen the assembly date of the block and the build date of the car? If the car was built on Oct 15th what would the assembly date of the block have been? Sorry if this is a stupid question.

Regards,
Jerry

[Joe L.]

Addendum

Also, keep in mind that neither the foundry, the engine assembly plant, nor the vehicle assembly plant observed a "first in, first out" policy. As the late Phil Hawkins, formerly of St. Louis Corvette assembly, used to say "...we weren't in the grocery business; we didn't rotate our stock...". While he was talking about St. Louis Corvette, the same thing applied to all the other parts of the GM "manufacturing chain".

This means, for example, that 2 blocks cast on the same day might be machined and assembled at 2 completely different times. One could be done more-or-less right away (the norm), while another might languish for months before it was machined and assembled (the exception).

There tended to be more "lag" time associated with big block production than small block. I don't know why; the opposite should have been true. For small blocks of the period, the castings were manufactured in Saginaw, MI and shipped to Flint for machining and assembly into finished engines. The big block foundry of the day was co-located with the engine plant in Tonawanda, NY. So, theoretically, there could have been much closer time period between block/head casting and their machining and assembly. Sometimes, there wasn't, though. Still, close specing between big block component casting dates and assembly dates was the norm.

[Joe L.]

Re: 66 block stamping

Jerry-----

Generally, it should be at least a week prior to the car's build date. An engine being built in Tonawanda, NY, shipped to St. Louis, and installed in a car would usually take a bit longer than a week, but, depending on how a lot of things went (that no one cared much, at all, about at the time), it could have been that short of a period. More commonly, it would be in the 2 weeks to 8 weeks time frame. That's exactly the time frame you're talking about, assuming that the engine was assembled shortly after its block casting date (which would be the norm).

[Richard S.]

Re: 66 block stamping

Jerry,
There is a 1966 section in Noland Adam's 63-67 book that lists information he collected via surveys......you can follow the block casting dates and engine assembly dates as reported by many owners. He even seperates big blocks from small blocks. NCRS sells the book if you don't already have it.

[Jerry Weidner]

Re: 66 block stamping

Thank you Rick that is the information I am looking for, I will be purchasing the book but in the meantime I need to have an answer by tommorrow on the assembly date can who hss the book right now either fax me the pages regarding the 66 date to 716-825-7460 or email what it shows for the dates listed above? Any help would be greatly appreciated.

Regards,
Jerry

[John Lokay]

Re: 66 block stamping

Jerry,
Believe it or not, I'm pretty sure that the engine block for my L72 was cast the same date as yours (I-22-5) and it was assembled on 10-8.

[mike cobine]

Is this so you can stamp it original?

If so, you should know there is more than just stamping the date to make it correct. And if it is stamped and detectable, then it will look worse than not havign it stamped at all.

[Jerry Weidner]

Re: Is this so you can stamp it original?

Mike,

It is for a car I am looking at tommorrow, owner says its the real deal and I do not want to spend big bucks unless evrything is perfect. I have a little knowledge as I have had 5 corvettes but I do not know the little details as I have not seen a good restamp up close. I do know what the broach lines look like on an original and I just want to be well educated on the cast #'s and stamp dates.
Regards,
Jerry

[mike cobine]

Re: Is this so you can stamp it original?

As many have stated, the spread of dates on the assembly is pretty wide in most cases but in this case, you have to be after I 22 5 (9/22/65) and 10/15/65 which is only three weeks.

Since it probably was done a day or two after the casting normally, or at least a few days before the car date, you probably find one from 9/25/65 to 10/10/65 as the most likely dates.