Question: Is there a way to tell if my 67 came with f41 suspension?

[Vinny]

I recently purchased a 67 sb with a lot of options and while inspecting the rear end I noticed that it has a 7 leaf spring. I cannot verify that it is the original, however, It has the curled ends and is tapered. the liners appear to be original as well.
I know that the shocks and front springs were different for the F41 package. The shocks have been updated to KYB,s. Is there any way to tell if the front springs are f41? I need to replace the rear spring(sagging). should I get the replacement 7 leaf or go to a standard 9 leaf? The car is sitting pretty level because at one time a cushion added to the sagging side. I have new 215r7015 radial ta's. Does anyone have any thoughts on this and which way to go? Thanks, Vinny

 

[JohnZ]

F41 was only available in 1967 with the 427/435hp and L-88 engines, so the 7-leaf rear spring is a replacement. Small-block front coil springs had .600" wire diameter, and big-block F-41 front springs had .680" wire diameter.

The small-block front sway bar was 3/4" in diameter; big-blocks were 7/8", and big-blocks with F-41 were 15/16".

I'd stay with the stock small-block 9-leaf rear spring (140# per inch load rate); the 7-leaf F-41 spring rate is more than twice as stiff (305#/inch). Eaton Detroit Spring (www.eatonsprings.com) makes an excellent reproduction 9-leaf spring.

The front spring story is even worse; the stock small-block spring load rate was 195#/inch, and the big-block F-41 spring was 550#/inch.

 

[Vinny]

Thanks John, great info. I'll pick up the stock 9 leaf....Vinny

 

[ricks327]

I followed John's recommendation on the Eaton Spring and also took others advice and made sure that I got a bare spring versus the coated one. Not sure what the coating is but heard horror stories about trying to remove the coating prior to prep and painting.
Rick

 

[JohnZ]

I followed John's recommendation on the Eaton Spring and also took others advice and made sure that I got a bare spring versus the coated one. Not sure what the coating is but heard horror stories about trying to remove the coating prior to prep and painting.
Rick

Mike got the message, and stocks them both ways now.