66 bb rear leaf spring

[Bill H.]

What would be the more correct rear leaf spring for a 66 bb 427/390 ?
It should be a 9 leaf spring but which one?

One version of the 9 leaf spring has all 9 leafs curved and touching, The other version of the 9 leaf spring the 6 longest leaves were curved and the 3 short ones were straight. This spring is know in the spring world as a 6/3 spring and/or a two stage spring (aka variable rate).
Eaton offers both any suggestions?

I have a replacement spring without turned up ends so I'm not sure what was there originally.
thanks

[Michael G.]

Re: 66 bb rear leaf spring

Small and big block engines used the same spring. 6 arched leaves and 3 straight.....aka variable rate spring. Spring you have indicates a replacement spring.

[David L.]

Re: 66 bb rear leaf spring

The 1966 Corvette Specifications (dated September 1965) by the Chevrolet Engineering Center, Warren, Michigan, describes the rear spring as follows:

Type: Multi-leaf, 9 leaves
Material: Chrome carbon steel, heat treated
Length (developed) between eye centers: 46.36
Width: 2.25
Design load, lb @ - camber: 1360 @ .352
Defelection rate, lb per inch, @ design load
@ Spring: 140
@ Wheel (wheel rate): 123
Spring liners
Number: 7
Location: Between all leaves except numbers 6 and 7
Material: Polyethylene with graphite

[Bill H.]

Re: 66 bb rear leaf spring

ordered the 6/3 from eaton today
meets the specs above
thanks for your help

[Michael F.]

Re: 66 bb rear leaf spring

let us know how you like the eaton spring