C2 front spring replacement

[Daniel Grunwald]

I am in the process of replacing the front coil springs on my 67 big block, alum head, no air, no pwr. steering, car. The tires were rubbing at times when I turned the wheel while going up or down an incline,(such as a driveway). The springs also had 2 twist ins in each side already. The static height of the old springs is 12 inches. I am looking at the Paragon springs and thinking of the 13.06 static height springs as one inch seems like it would solve my problem and the ride height should be about right. These springs have a 507 lb. spring rate and I do not knowif that is correct or not. I seem to remember something about 460 lbs. but I am not sure if that is correct. I really don't want to install them and have an incorrect spring. Also, when I used a fork to break loose the lower ball joints ,(which seem to be original and in good condition), I put a tear in the rubber grease cover. Where can I get a new cover without having to buy the new ball joint? The car is low mileage and I didn't want to replace the orig. riveted ball joints if I don't have to. Any suggestions or advice will be appreciated.
Thanks, Daniel

[Joe L.]

Re: C2 front spring replacement

Daniel-----

The original spring used for your car was GM #3888250. My records show that this spring had a free length of 17" and 9/16" wire diameter. I seriously doubt that a spring of 17" original free length would have "fatigued" down to 12". So, if you have standard big block suspension, I don't think that you have the correct springs in the car now. The F-41 springs were of 12" free length, but have 11/16" wire diameter. Reproductions of the GM #3888250 spring are manufactured by Eaton Detroit spring, but I don't know good they are. Dr. Rebuild also sells a spring for your application.

As far as the ball joint seal goes, GM never sold a replacement for original-style ball joints. As far as I know, they are not available in reproduction, either. Even if they were, it would be difficult to install one since the originals are secured to the ball joint with a factory-installed metal band. The only thing that I could suggest would be to try and find a used ball joint with a good seal. Then, you'll need to find a way to remove the seal and install it on your ball joint. The seal doesn't have to come from a Corvette ball joint. Many other Chevrolet of the period used ball joints with the same seal.

[Mike McKown]

Ball joint boot

Dan:

Someone made the same inquiry on the damaged boot about six(?)weeks ago. My suggestion was to use super glue. It will bond rubber together. Read the label to make sure. Somebody else jumped in and suggested something else that seemed to me might be a little better. I can't remember what it was.

Mike

[Wayne C.]

Joe: front spring height

Adams' Volume 2 has a chart on page 450 that gives some spring dimensions; unfortunately he differs from the 427 spring free height Joe gave... he says 14.26 inches, with a working height of 9.98, same working height as a small block, whereas the F41 spring has free height of 14.26 and working height of 8.56.

Hard to know who to believe, when one has to choose between Joe and Noland... luckily, I don't have a 427 car, so I don't have to make that choice!

[Daniel Grunwald]

Re: C2 front spring replacement

Joe,
The springs that I have out are indeed 11/16 wire and 12 inches in free height so that would be an F41 probably. What is an F41?
Thanks, Daniel.

[Joe L.]

Re: Joe: front spring height

Wayne------

I've noted the differences myself in the spring dimensions which Noland provides in that table. My dimensions are, basically, "empirical". They were obtained by direct measurement of NOS springs with GM tags still on them and showing the particular part number. In the case of the '250' springs, though, the measurement was done by someone else, and I have not personally verified it.

[Joe L.]

Re: C2 front spring replacement

Daniel-----

F-41 is heavy duty suspension. If the car was originally so-equipped, the rear spring should be a 7 leaf. However, either the front and/or rear springs could have been changed and the car retrofitted with F-41 springs.

Corvettes with F-41 suspension typically have a slightly lower ride height than standard suspension.

[Wayne C.]

Re: C2 front spring replacement

Joe, my 53-76 parts manual gives these springs for a 67:

3832518 for sp. perf. susp, HD susp

3888251 for 327 h/perf (so, is this the standard small block spring?)

3851100 for 427

3888250 for 427 (exc C.A.C), or 427 h/perf (exc sp. perf. susp.)

I don't quite understand 3851100, since it doesn't say "w/C.A.C" and so it seems to overlap 3888250.

Noland says standard small block 67 spring (3888251?)has a free height of 16.82 with 12 coils, ....no wire diameter given.

I'm trying to identify a couple of used Corvette springs that are supposedly 66 or 67 vintage.

Do you have these dimensions:
3888251 (wire dia),
3851100 (fh, # coils, wire dia),
3888250 (# coils)?

[Joe L.]

Re: C2 front spring replacement

Wayne-----

I think there are some errors in the 1976 P&A Catalog you have.

First, the GM #3851100 was, primarily, a small block spring used from 1964 through 1967. However it was used for 1965 L-78 and, perhaps, early 1966 L72 and L-36.It is 15-3/8" free length, 11 coils, and 19/32" wire diameter.

The GM #3888250 was used for most 66 and 67 big block applications, except F-41 or A/C. According to my information, it is 17" long with 9/16" wire diameter. I don't know the number of coils.

The GM #3888251 was used for 66 and 67 big block with A/C applications. It has 9 coils, but I don't have other info on it (I have some NOS examples of this spring[none for sale] but I don't have the time to get them out).

GM #3832518 was used for ALL 63 through 74 Corvette applications with F-40 or F-41. It is 12" free length, 7 coils and 11/16" wire diameter.

[Daniel Grunwald]

Re: C2 front spring replacement

Thanks Joe!

[Wayne C.]

One more question, Joe

Darn!!! The spring I really want to identify is 12 coils, 16.6 inches free height, and 19/32 inch wire diameter. Bought the pair with some other Corvette stuff, supposedly all from the same wrecked 67 Corvette, but I never saw the car. Doesn't match any of the spring specs you gave.

However, interestingly, Noland's chart shows 12 coils (not 11) for the small block spring, and 16.82 free height... no wire diameter, but my spring matches your small block spec... is it possible your information lists "active coils", which I believe is usually 1 coil less than actual count?

[Joe L.]

Re: One more question, Joe

Wayne------

Coil count is the most "imprecise" element of a spring's description. So, it's very possible that one can be "one coil off" in such a count. I strongly suspect that the spring you have is a 3851100.