[QUOTE=Mike Ward;

"Individual sheets were changed/updated in the AIM every time a component changed fit, form or function. Given that there were always running changes on these cars, sheets might have been update daily or weekly.

The AIMs we have now don't necessarily represent the last day of production, the first or anywhere in the middle. Pretty much a mishmash of somewhere"



Interesting comment, as I have only ever seen the final engineering level on each page. What makes you say that there are some pages that show middle of production engineering levels?

 

It varies from year to year, but have a look at the revision dates on the pages. They're all over the place. For- instance, the AIM for my '73 does reflect the change over to the '74 front grills made approx. a month before completion of that year's production.

Some AIMs being distributed today were made up of various copies collected from the production facility to make one 'good' master.

Even if a given AIM were to represent the very last car coming off the line for that production year, it would still not illustrate the changes that were made to a component or system during the year. 'Not accurate' in the eyes of the guy who owns the first car off the line almost a year earlier.

 

We agree on this point. My '72 AIM shows engineering change history throughout the model year.

There were some running changes and some coordinated changes. The difference in these changes are around "system" items and obsolescence. An example of a coordinated change was the seat belt warning system. To comply with federal regulatory mandates, the passenger seat needed to have an occupant detection sensor after (about?) Jan 1, 1972. To effect this requirement, a sensor was added to the under side of the seat. Along with the sensor, a new wiring harness was required as well as an audible warning buzzer, a label on the LH sun visor, etc. This change needed to be coordinated so that all the different components involved in the change were changed together.

Running changes were typically not as significant, usually made to improve function or to reduce cost. Sometimes it took a while for the change to find its way from the drawing board to the assembly plant. My AIM shows the addition of 2 rectangular rubber pads to the leading edge of the convertible deck lid in early August 1971 (after the model year BOM was finalized). These pads were added to protect the paint against the seat release bezels when the seat was extended all the way back. My car was built in late August, and although the drawing and engineering history shows the addition of the pads prior to my car's build date, they are not there, showing me that the change hadn't found its way to St Louis yet. I also have a left over '71 radio (green characters) instead of the expected white. I have found other items like this as well, proving your point about how different an early car can be from the AIM. Changes that were made and then superseded by other/later changes are lost on the drawings themselves, however, should be reflected in the engineering history block on the dwg.

Because of my early build date situation, I need BOTH, a '71 and a '72 AIM.

 

72s and 73s used the same diagram.

 

I guess we never stop learning till we part this earth.
Thank you Mike Ward and like wise to you Easy Mike, our muscle cars in OZtralia didn't start till the late sixties and at the time customers could purchase a Value Added Vehicle (choose colour, stripes, trim etc.) but the schematic for a '69 IS just that with no variation, so you can see I am in unchartered waters. I'm good for now Thanks Again but no doubt I will pop up again with another concern. .... Bye for now!