78' rear spring?
08-06-2003, 06:03 PM
#1
Le Mans Master
Thread Starter
78' rear spring?
My 78' has the FE7 (Gymkhana) suspension and the book says it should have a 6 leaf 2 1/4 wide spring (which it has). In checking the calalogs for a replacement, all I see is 7 and 9 leaf. Will any of these subsitute for the 6 leaf?
08-07-2003, 10:12 AM
#3
Safety Car
Re: 78' rear spring? (Duke94)
It should be a 7 leaf. Count the little dinky one on top too. FE7 per the restoration manuals is 7 leaf.
08-07-2003, 07:38 PM
#4
Safety Car
Re: 78' rear spring? (Duke94)
My 78' has the FE7 (Gymkhana) suspension and the book says it should have a 6 leaf 2 1/4 wide spring (which it has). In checking the calalogs for a replacement, all I see is 7 and 9 leaf. Will any of these subsitute for the 6 leaf?
What book as someone else raised? Here's the deal...FE7 changed the rear leaf configuration 3 times between 75 - 81...from 7, to 6 and then to 9. The crazy thing is 78 is specified at 6 leaves with 5 spacers with of 2.25". So the specs you are ready are accurate and correct for the 78. What you are seeing are the AVAILABLE replacements and the spring rates do vary which suggests you may have ride height differences if you install the replacements.
So my next question is why do you want to replace it?
BTW...I'm curious what the shock numbers you have with FE7 in 78...can you get them?
08-07-2003, 08:05 PM
#5
Le Mans Master
Thread Starter
Re: 78' rear spring? (hunt4cleanair)
The book I refer to is "Corvette Restoration Guide" by Richard Prince. He states"the 6 leaf FE7 rear spring used in 1978 and 1979 is 2 1/4 inches wide while the standard suspension rear spring is 2 1/2" wide. To compensate for the decreased width, FE7 springs mount to the bottom of the differential cover with 2 spacers, one in front and one in back". I want to replace the spring because it has lost its arch. I contacted Eaton Detroit Spring (listed in the GM restoration parts book as the supplier) and they said 7 leaf 2 1/4 is the replacement.
08-07-2003, 08:27 PM
#6
Safety Car
Re: 78' rear spring? (Duke94)
Well it has more to do with spring weight than leaf count. our original 6 leaf FE7 spring had a spring rating of 307 lb/in whereas the 7 leaf FE7 spring in 76-77 came in at 305 lb/in.
So my suggestion is to ask them about the lb/in and determine if it comes it at this amount. I suspect it will be ok..most FE7 leaf springs had a rating of 305 lb/in...78 was rated heavier probably because it was the heaviest C3 of the entire generation.
Do you still have the original FE7 shocks?
So my suggestion is to ask them about the lb/in and determine if it comes it at this amount. I suspect it will be ok..most FE7 leaf springs had a rating of 305 lb/in...78 was rated heavier probably because it was the heaviest C3 of the entire generation.
Do you still have the original FE7 shocks?
08-08-2003, 08:53 PM
#7
Le Mans Master
Thread Starter
Re: 78' rear spring? (hunt4cleanair)
Huntforcleanair,
the original shocks are long gone. Best I can do is give you the P/N from the Assembly Manual:
Front L48 w FE7 & L82 all= 4984577
Rear FE7= 4984578
Hope that helps
the original shocks are long gone. Best I can do is give you the P/N from the Assembly Manual:
Front L48 w FE7 & L82 all= 4984577
Rear FE7= 4984578
Hope that helps
08-09-2003, 06:18 AM
#8
Safety Car
Re: 78' rear spring? (Duke94)
Thanks Duke...for some reason I missed that in the AIM...probably cause they are organized so well but thanks.
But the other thing I noticed that L82 nonFE7 cars got the 77 78 HD shocks...if I understand that correctly along with M20 L48 trannys.
[Modified by hunt4cleanair, 6:19 AM 8/9/2003]
But the other thing I noticed that L82 nonFE7 cars got the 77 78 HD shocks...if I understand that correctly along with M20 L48 trannys.
[Modified by hunt4cleanair, 6:19 AM 8/9/2003]
