1969 Nova L78 Rear Leaf Springs

[JRSully]

My May 70 L78 Nova w/ F41 and rsb came with the 4 leaf set up. I heard that spring selection was determined by options ordered/added on the vehicle at time of ordering, who knows for sure on that though

[1969l78]

My 69 L78 survivor car has the 5 leaf. Its a march of 69 car.

[YENKO DEUCE REGISTRY]

The option list did dictate spring selection, but I think it was more for the front coil springs as opposed to the rear leafs. I think there was really only two spring packs, and the HD version could be either the 4 or 5 leaf version depending on what was brought to the line.

[Mr.Nickey Nova]

My Jan. built 70 survivor L34 still retains it's original 4 leaf setup which i always thought was the heavy duty type due to the thicker springs.So,is the F40 a HD suspension and the F41 a performance suspension with the 5 leafs?? I have heard all kinds of different stories on this subject.

[JRSully]

FWIW,I know my May 70 L78 still had the original blue HH spring tags on the front coils, has the 13/16th Front sway bar and the 11/16 rear bar with 4 leaf set up. It was all undisturbed when I got the car.

[YENKO DEUCE REGISTRY]

The F41 option was bars and shocks, not springs. So, it is not uncommon to find a Sully car vs. a Yenko Deuce - both with F41, but with different spring packs (one with 4 leafs and others with 5). The 4 leaf packs are not so much 'heavy duty' due to their thickness, they are thick so as to fill the spring pocket - it's the same pocket for both the 4 and 5 leaf packs.

[69SSZL1]

Good info here: http://www.chevynova.org/index.html

[Nova Research Project]

Short version for the record:

69 L78 HD F40 had BK coded 5 leaf springs 100 pound rate(Listed as RPO on the spring calculators)
69 L78 Special Purpose F41 (springs and shocks only) had BG coded 4 leaf springs 125 pound rating (listed as HD on my spring calculators on my site)

In 70 they renamed the Heavy Duty F40 to Special Suspension and the F41 was called Sport Suspension and added the rear swaybar late in production, however they were the same springs as 69.

But yes springs were computer selected base on weight and options. That is why the LT1 used the BK 5 leaf as its F41 Sport Suspension vs the stiffer BG 4 leaf. The lighter block yielded over all less weight and required a lighter rated spring.

Both the 69 and 70 spring calculators are on the projects section of chevnova.org.

Greg