Category Archives: Auto Manufacturing

When you are restoring a car you have a lot of choice to make.  Keep the original paint or engine? Drop it a couple of inches? Upgrade the suspension?   Of course there’s the brain racking choice of the what time of necessary parts shop for as well.  Do we go with NOS?  How about OEM, used or remanufactured parts or rebuilt?   These last two question important, however you are going to need to know what the differences are between them.

NOS is New Old Stock and not normally pronounced as a word, just initials  N.O.S.  These initials normally refer to parts that were made by the car’s manufacturer (like GM, Ford, Chrysler) and are stocked at dealerships or auto parts stores while the cars are ‘current’ in marketplace.  Finding NOS parts for you 1930’s Studebaker is a huge deal, provided the parts lasted sitting in the box for 30 plus years.  Automobilia collectors get down right giddy if they find a spark plug for a Model T in the original box – so there’s that aspect.   But many car collectors will look for these parts when on a car when buying and selling.  So NOS is not always going to get the job done if you want a great running classic car and you can almost bet that some are budget busters!

Ford NOS Spark Plugs

NOS Thunderbird Windshield wiper motor

That’s why, in part, all the other classification of parts now exist.

Let’s look at the  remanufactured classification of parts.  The idea is that the parts are as close to new as possible. Any of the parts that might wear have been replaced (normally as standard procedure) and the core material is thoroughly gone over to see if it measures up to original equipment specifications and therefore perform as you would expect original equipment to perform.  The replaced components of the part (seals, springs, gaskets, etc.) should be made in the same process as the original parts were produced and those too should be test against original specs.  This goes for something as small as a distributor caps to a complete short or long block engines.  You’ll  find prices will often cost less than NOS parts and will carry a warranty, which most of other categories do not.

Another classification that is often confused with remanufactured is ‘rebuilt’ parts.   Rebuilding parts includes thorough cleaning and inspection.  Parts that are worn (and not capable of meeting manufacturers’ acceptable wear limits) or broken are replaced.  Anything serviceable is retained.   This leads to a combination of used components (from a core unit), new components (gaskets, washer, etc.) and original.  Quality is an issue and will vary between different rebuilders and sometimes  even from the same rebuilder.  Rebuilt part do come with a “limited” warranty.  Just in case “core unit” isn’t a  familiar phrase, it is basically your old part handed in for a rebuilt part.  Often the cost of the rebuilt part has a ‘core’ charge attached.  For example, when purchasing a rebuilt alternator, the price of $150.00 includes a $25.00 core charge, meaning if you turn in your malfunctioning part the part cost $125.00.  In turn the company uses your core for rebuilding or salvaging parts for another rebuild.

Original Equipment Manufacturer or OEM classification of parts can be confusing as well.   OEM’s were companies that produced parts for the auto manufactures.  For example GM didn’t produce its own batteries, they looked to Delco or some other expert to produce these parts.  You may still be able to buy a battery from Delco, however it may be cosmetically different (which sets it apart from NOS parts.).   In some cases the manufacturers will license a company to produce parts to their specification.

Used parts is the last classification we going to discuss.   Just as you might expect, these are parts most often obtained at a salvage yard.  There the parts may or may not have been tested and there is no quality control.  As you  may have guessed, used parts of often less expensive than the other classifications, but they are not covered by any particular warranty.

Salvage yard parts – untested and as is.

Determining which classification of parts to select from depend on several factors.  What is the end goal for the car?  Concourse restoration, race and show, racing only, just a good-looking classic or muscle car to woo the neighbors and cruse the streets.  What is the budget?  The average guy has average skills, average tools and an average guy’s budget constraints (family, bills, etc.) this may determine the level of restoration you can afford.  Is the need part available? It is great to start out with the goal of restoring to 100% original but if the NOS parts are not available, then what?

In my last restoration (1970 Mustang) I used all manner of parts.  NOS parts from online, used brackets for the A/C compressor (from a Mercury), OEM parts from overseas and rebuilt 4 speed trans from a wrecked Shelby Mustang and a new intake and carb.  This car turned out great and it was raced and woo’ed over and even brought home a couple of car show trophies.

Enjoy the hobby and thanks for reading.

Tim