By Wayne Scraba
In the last issue, we devoted space in our Paper Chase series to various factory and aftermarket service (shop manuals). If you recall, there were plenty of different ways to either obtain copies of those manuals or to view them online. But in truth, those weren’t the only useful factory (and other) reference publications out there. Included in the mix are GM Assembly Instruction Manuals (AIM’s), parts catalogs, parts illustration catalogs and even a really cool reference book called an “interchange manual”. Here’s the inside scoop:
This publication is GM “Assembly Instruction Manual”. In essence, this is what the factory folks used while they were putting the car together. Obviously, there’s a ton of info contained within.
Assembly Instruction Manual…
Reprinted Assembly Instruction Manuals or "AIMs" are available for many popular GM-build vehicles. These books are copies of the actual manuals used on the assembly line as the vehicle was being built. Printed in a loose-leaf format, the AIM includes large drawings of all components and sub assemblies that are pieced together during the manufacturing process. These drawings show where the parts go and how they go together. Part numbers are included, but we should point out that these are production part numbers, not service (over-the-parts counter) part numbers. Because of this, the part numbers shown are sometimes unobtainium (of course, there are numerous situations where the parts were readily available from your dealer, but that’s another topic entirely). Additionally, the Assembly Instruction Manual will also show you where and how specific hardware is mated. It will also provide info on correct fastener installation, proper clamp location and orientation, the correct location of pierced holes as well as ride height specifications. Much of the AIM is filled with regular production options. Here, the manual will also provide insight into correction location, mounting points and unique torque specs for many components found on the car.
GM’s Assembly Instruction Manual is broken down into two parts. The first segment examines roughly a dozen basic assembly steps that range from labels to stickers to complete electrical installation. This part of the AIM is titled the "Uniform Parts Classification". Following the UPC section is the RPO or "Regular Production Option" section of the manual (obviously the part that deals with optional equipment). The manuals contain cancelled options too: They’re listed along with the dates of cancellation and other appropriate updates. Bottom line here is, they’re a great workshop companion – even if you only use it for the big blown up illustrations that show how parts mate together.
So where do you find them? They’re available from any number of restoration parts houses. Basically, search for a company that specializes in parts for your GM product and check out their catalog. You can find AIM’s for all sorts of different GM vehicles with a little bit of digging. What about online? Sorry, but we’ve never run across an online version.
There are a number of different parts catalogs printed over the years. We prefer to use vintage catalogs printed a couple of years after the model year of the car you’re working on. These two are GM catalogs.
Parts Catalog…
Original parts department catalogs along with reprints of vintage parts catalogs are readily available. These catalogs not only list the part numbers for various components, they also feature blow-up illustrations of various components. Some are split into parts catalogs and illustration catalogs. Others are combined. Try to get a catalog that is perhaps dated a year or two later than the car your working on. That way, the parts numbers will be more stable (it seems like there were fewer change ups as the years progressed). Obviously, most part numbers will be discontinued for vintage cars, but they’re still a great source of reference.
Here’s a well-known vintage Ford catalog. It’s the Green Parts and Accessories catalog that covers 1928-1947 Fords. FYI, this is available as a reprint.
For later model year cars, there are plenty of online OEM parts catalogs. Case in point is GM Parts Online. They have a massive collection of parts for GM products, typically ranging from 1990 onward. Remember that as the year’s progress, more and more parts are discontinued. Here’s a link:
GM Parts Online (later model GM Parts)
Discount Ford Auto Parts is similar to GM Parts Online. Discount Ford has a searchable base ranging from the early eighties up (not all cars are covered). It’s much like the GM Parts Online setup where you look up the part you need (by description or part number) and it will spit out the part you need and in some cases, you’ll get an illustration. Like the GM bits, there are a lot of unavailable parts for older models.
Discount Ford Auto Parts (later model Ford Parts)
For Mopar applications, a good bet is Buy Mopar Parts Now. It’s like the two above. It caters to later model Chrysler, Dodge, Ram and Jeep models. It too has a good selection of illustrations. And like the other two, there are plenty of discontinued parts as the model years increase in age. Here’s the link:
Mopar Parts Now (later model Mopar Parts)
The Hollander Interchange Manual is the grand daddy of all swap and interchange books. Our copy is huge and well used! Check out the text for more info.
Hollander Interchange Manual…
We saved the best for last. The Hollander Interchange manual is pretty much the Holy Grail of parts scrounging. Locating parts for your vintage can sometimes appear to be like mission impossible. But as we all know, many pieces are direct interchanges with other similar (or not so similar) "corporate" offerings. For example, an unassuming Cutlass four-door sedan can supply a host of goodies for something like a vintage Ram Air GTO. Items like suspension pieces, electrical components, some transmission components and even certain trim parts and believe it or not, any number of accessory or optional equipment parts can prove to be virtually identical. Best of all, it applies to all makes – GM, Mopar, Ford and AMC. Keep in mind too that when you find an interchange for a part that’s common with something like a four door sedan, you know you can save serious coin.
Fair enough, but how is it possible to figure out what interchanges and what doesn’t? That’s easy! An outfit called Hollander provides huge manuals to wrecking (recycling) yard industry. Each of these manuals shows the interchanges between respective vehicles. The Hollander manuals used by wreckers are typically four inches thick and include all sorts of information parts along with ways to ID those bits. Little items such as trim pieces are not included, but a careful scrounge of likely similar corporate vehicles at a salvage yard can easily turn up the small parts.
At one time, the only way to get a Hollander was to find a cast-off from the local wrecker (err….”recycler”). But today, you can buy them direct from Hollander. They even have small model specific manuals (for example, a Nova interchange manual).
If you step up and buy a Hollander for something like a musclecar project, purchase the 1964-1974 issue, Volumes 1 and 2. This is an expensive package, but the dollars saved during the restoration will be well worth the expense. Naturally, Hollanders are also available for other model years. Hollander has a specific section of their website devoted to collector cars. They also offer a massive electronic database (CD), however it’s very costly (the print books aren’t that bad). Here’s a link to Hollander:
Hollander Interchange Manuals (full range of manuals)
As you can see, there’s plenty of “Research & Reference” information out there. You just have to harvest it! You can check out the accompanying photos for a closer look:
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