1967 barracuda formula s rear sagging

Bad Sport said
I agree on the ESPO. Changing them is a breeze, as long as the current bolts come loose.

Prop the car up on jack stands under the frame rail in front of the springs. Put another under the axle tube on the side you are working. Drop the spring out, put the new in. Repeat on the other side.

Leave the bolts a tad loose until you get it on the ground and torque to spec.

IF all goes well a couple hour job if you're not familiar with it.

Torque to spec. Good point! a quote from a prior post by YoungBlood.
"I'm almost where you are, and I've been instructed that 45lbs is where you want to be for the u-bolts.

The leaf-spring needs to effectively "suspend", and cranking down too much prevents this, keeping the spring from working as designed (correct pinion-angle is very important to this function as well).

Tightening down too much will affect both traction and ride."