Are all F40/41 springs the same? Do they all have evenly spaced coils? My 69 has F41 parts for the bars, rear spring, shocks, shock mounts but has a progressively wound front spring. My understanding is that F40/41 front springs are constant rate. I have read here that one can buy a Moog 658A and cut it down to 7 coils and have a F40/41 spring. What are the options? Thanks.
-
-
Re: Are all F40/F41 front springs the same?
Good question! All heavy duty F-41/40 front springs were the same from 63 thru 71 (PN 3932518).
Cutting down a spring to seven coils will NOT make it an F-41 spring. The diameter of the wire wound coils are larger for the HD suspensions. Cutting down a 9 coil spring will just make it shorter!
JR -
Re: Are all F40/F41 front springs the same?
All F41 springs are the same, you include F40 which just might have a difference in the 427 category...Comment
-
Re: Are all F40/F41 front springs the same?
My understanding is that the Moog 658A (for a BB Impala) has the same wire diameter and coil diameter and spacing as an F 40/41 spring but is longer (before cutting). I realize that cutting a standard corvette spring would not work.
It is surprising that BB and SB F40/41 cars used the same spring since the BB cars are carrying at least 150lb more on the front wheels. This must equate to about a half inch of ride height but I have not seen different ride heights discussed in service manuals.
Mike
Comment
-
Re: Are all F40/F41 front springs the same?
I bought the 518 spring from GM many years ago and installed them in my 1970 coupe. I initially thought that the 518 spring being a stiffer spring than what my 70 came with from the factory that my car would sit higher in the front.
My 70 has power steering and air conditioning and I wanted my 70 to sit higher than what the factory springs were providing after years and many miles of service.
This did not happen with the installation of the 518 springs. I did not do an actual measurement before I changed the springs, but it appeared to be the same height after the change.
The 518's were of course stiffer than the originals and I liked their performance.
Vette Brakes sells or perhaps sold at one time a stiff performance spring. I have a pair that have never been used. My 518's are not installed in my 70 right now and sitting side by side with the Vette Brakes springs they pretty much look alike.Comment
-
Re: Are all F40/F41 front springs the same?
Mike------
It might be surprising but that's how it was. The GM #3832518 spring was used for all 1963-72 Corvettes with F-40 or F-41. It was also used for 1973 Corvettes with FE-7 (part of Z-07 for 1973).
What's more, the GM #3832518 spring was the ONLY coil spring which was used for both C2 and C3 Corvettes. Otherwise, there was no commonality, at all, between C2 and C3 coil springs, PRODUCTION or SERVICE.In Appreciation of John HinckleyComment
-
Re: Are all F40/F41 front springs the same?
Mike,
The F-41 front spring was originally known as the Talladega spring and the really big (shorter) spring was known as the Daytona spring PN 3986032 with an 860lb rate. They did not get tight between the A-arm and frame until you let the car down on the ground. Want some really big wire and a short spring. Find a Daytona spring.
JRComment
-
Re: Are all F40/F41 front springs the same?
Correct me if I am wrong but in 1968 -up GM started using springs rated for different options like a 427 with A/C got a different spring than 427 with P/S.
In prior years there was F-40 then standard suspension and finally A/C so just three springs.
Comment
-
Re: Are all F40/F41 front springs the same?
Tim------
There were more than just 3 coil spring part numbers used for the C2 era. For example, 1966 big block had springs for C-60 and non-C-60 applications.
Beginning in the C3 era there were more specialized spring applications but there was not a huge number. Starting in about 1973 the installed spring was determined by sprung weight and there were about 4 or 5 springs for any given model year.In Appreciation of John HinckleyComment
Comment