With the prospect of cooler weather ahead, I'm planning to restore the front suspension of my 67 big block AC Coupe. I have researched the archives and read many stories about unsatisfactory spring replacements. The existing springs are definitely tired as the front end of my car is about two inches too low. I have an original set of front springs from a non-AC big block car that look like they are in good shape, although they have been painted with cast blast. I really don't want to go with repros after all the stories I've read and the a few cars I observed at Carlisle this year that didn't "sit right." Is there anything that can be done for my existing springs? Will the non-AC springs give me the correct height? Are there any negatives to using these springs on an AC car? Are there any NOS big block A/C springs available anywhere?
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Re: C2 Big Block AC Front Springs
John-----
There is no effective way to restore or "rejuvinate" a coil spring. Something that you may be able to do is to install hard rubber cushions in the spring seats to effectively shim up the springs and restore proper ride height. GM may even have used these cushions in some original A/C applications before they developed special springs to accomodate the higher weight in A/C applications. However, as far as I know, these cushions are no longer available from GM. "Shimming up" the coil springs is not a perfect solution, but it is an acceptable solution if you can find the special rubber cushions. NEVER, EVER use spring spacers which install between the spring coils.
I don't think that the non-AC springs will produce a satisfactory ride height. You'll likely end up just about where you are now, especially if the springs are used. I'd check your existing springs, though, for free length (their length in the out-of-car, uninstalled, uncompressed condition). Unfortunately, I don't have the free length spec for this particular spring, originally GM #3888251.
NOS examples of the 3888251 spring? Very difficult to find, I'm afraid. Dr. Rebuild used to have some available, but I don't know if he still does. Dr. Rebuild also used to have the spacer cushions, but I don't know if he still has these, either.In Appreciation of John Hinckley -
Re: C2 Big Block AC Front Springs
While I didn't talk to the Dr. himself at Carlisle, the person I spoke to in the Dr. Rebuild booth thought that they no longer had any of the original springs for AC applications. I have resisted putting any spacers in the springs as I had a bad experience with spacers in a 1968 AMX a long time ago. I have been collecting parts to do this job for over two years and have the original ball joints, idler arm, bushings and other parts I need to complete the project, however from all the posts I have read and cars I have seen, the spring seems critical to a satisfactory result.Comment
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