1966 427 AC Delco front coil springs

[Tony C.]

Hi

I found a guy that has 2 sets of new in the box Chevrolet AC Delco front coil springs for sale for $50.00 a set this is what is reads on the box AC Delco front coil springs 45HO172 GM 88913485 GR 7.412. I was going to get a set from Eaton Spring co. would the AC Delco be a better spring and better choice
Tony

[Joe L.]

Re: 1966 427 AC Delco front coil springs

Tony------

The AC Delco parts you described are, basically, an aftermarket-type product. They are not necessarily the same as the original springs. However, they may work ok; I've not had any experience with them.

[Geoff C.]

[Joe L.]

Re: 1966 427 AC Delco front coil springs

Geoffrey------

Yes, all of the Corvette coil springs were previously discontinued without supercession; there was no supercessive part number for them after the last "iteration" was discontinued. They have been "dead" for quite a few years now.

The "889" series of 8 digit part numbers began several years ago. I believe that this series of numbers is assigned to AC-Delco and is used mainly for aftermarket-type parts sold under the AC-Delco brand. Parts for quite a few applications that had been previously discontinued entirely from GM became available again through AC-Delco. These include things like coil springs, clutches, suspension parts, some electrical items, and other parts. However, the lineage of these parts is not the same as the original PRODUCTION and SERVICE parts. These are SERVICE-only items and are an aftermarket type part; they are NOT a PRODUCTION-type part, at all.

Delco was always a supplier of BOTH PRODUCTION-equivalent SERVICE parts as well as aftermarket-type parts. Many of the PRODUCTION-type SERVICE parts were manufactured in Delco parts making operations. Since DELPHI was "spun off" from GM, most of GM's parts manufacturing operations are no longer GM. DELPHI drastically reduced the amount of SERVICE parts for older applications that it manufactured for GM. So, GM had to find other suppliers for the parts that it intended to still offer through AC-Delco.

The short of it is most of these parts are, as I say, aftermarket quality parts. They are much more "generic" and are absolutely not of the same quality as OEM, PRODUCTION-type parts.

As you noted, many of these parts show the "SPS" source. GM PRODUCTION-type parts rarely have an "SPS" source (except for bulk items like interior upholstery material, etc.). Basically, what happens here is that aftermarket parts are boxed at the manufacturing source in AC-Delco boxes and shipped directly to the ordering dealer. The same source probably has stacks of boxes with all sorts of different brand parts and does the same thing for NAPA, Kragen, Autozone, etc. Since DELPHI is pretty much out of the shock absorber business, most of the GM SERVICE shocks these days are manufactured by others. So, you'll see a lot of shocks with "SPS" source, too.

I expect that the springs are manufactured by Moog or Monroe and boxed for AC-Delco. A lot of GM SERVICE shocks are manufactured by Monroe or Gabriel.

[Geoff C.]

[Joe L.]

Re: 1966 427 AC Delco front coil springs

Geoffrey------

Yes, coil springs are a component that was traditionally never offered by Delco. The same thing is true of clutches. They were never offered through Delco, either. However, both are now. There are some other parts that were never traditionally offered by Delco that are now, too. In days of old, shocks were both manufactured and marketed by Delco. Now, they're just marketed by Delco.

Keep in mind that AC-Delco is GM's aftermarket parts system. It's not really connected to the old Delco parts MANUFACTURING business. AC-Delco is just a parts MARKETING organization now. While many of the AC-Delco branded parts are available through the GM parts system, they are aftermarket-type parts---not the OEM-type, same-as-PRODUCTION parts that one is accustomed to obtain through the GM parts system. Some of the AC-Delco parts, even those with the long number, are not available through the GM parts system, though.

Actually, I don't think that these springs are connected in any way to the "GM Restoration Parts" program. If they were, I don't think that they'd be marketed through the AC-Delco parts system. I think that they're just aftermarket parts packaged in AC-Delco boxes. For example, I know that the AC-Delco clutch kits are simply Sachs/LUK aftermarket clutch kits packaged in AC-Delco boxes. They are very good kits, but they are NOT the same as the GM OEM parts once available through the GM parts system.

One other thing: GM Restoration Parts usually carry the original part number (regardless of just how much they represent an actual reproduction of the original part). In fact, I think that's the main thing that is provided under the program---the rights to use the original part number. These "889" AC-Delco parts have no reference, at all, to the original part number. They are not even shown as being supercessive to the original part number in most cases.

[Tony C.]

Re: 1966 427 AC Delco front coil springs

So would you think a AC-Delco GM aftermarket coil spring is as good as Eaton Spring Co. coils or better.
Tony

[Joe L.]

Re: 1966 427 AC Delco front coil springs

Tony------

I'm afraid that's a question I don't have an answer for. I'm fairly sure that the AC-Delco product is produced by one of the major chassis parts manufacturers like Moog. So, I feel pretty confident regarding the quality of the part. I'm sure that it will perform ok, too. However, the big question is will it produce the correct ride height? I don't have an answer for that. As I mentioned, these are aftermarket-type, REPLACEMENT springs; they are not reproductions of the originals, although they MAY be very close to the originals in configuration. On the other hand, they may be very different than the originals in configuration and still perform properly AND produce the correct ride height. That's how it often is with an aftermarket-type, REPLACEMENT part.

The Eaton springs are SUPPOSED to be exact reproductions of the original part number. They are licensed by GM to reproduce the original springs and they have the original drawings. Whether the springs that they manufacture are correct and true to the originals in every way is unknown. As I have said before, unlike the original parts, there is no OVERSIGHT that I am aware of in the GM Restoration Parts program. In other words, no one checks the parts to ensure that they conform to the original specifications as GM did when the parts were produced for them. So, it's left up to the licensee. Many times, there is only a "cosmetic" connection between the original part and the reproduction. That might be ok for things like emblems and trim but it's not ok for mechanical parts if they are to perform in all ways like the original part.

One of the big factors here is manufacturing and tooling limitations. Original tooling used for PRODUCTION and SERVICE parts was very expensive. Its cost was amortized over very large manufacturing runs. If the original tooling has been scrapped or is worn out, re-creating original tooling which will produce an original-in-every-way-type part is far too expensive for a current day reproduction source. In other words, without the original tooling, even if one has the original drawings, one might not be able to reproduce a part as-original.

Also, there are manufacturing limitations. The original parts were manufactured using original tooling and often by major manufacturers with sophisticated, high-dollar manufacturing machines and facilities. Such manufacturers are not willing to produce small parts runs, even if they are supplied the original tooling. Without their manufacturing capability, it may be impossible to produce a part like the original and very few reproduction parts suppliers, including those licensed through the GM Restoration Parts Program, are going to be able to justify a parts run even at the minimum lot size that the major manufacturers are going to require. The restoration parts market just isn't large enough.