Smoke 'em if you got 'em
I'm currently running two passenger side 2800 lbs Super Stock springs on my 1970 440-6 'Cuda. This was at the recommendation of Dr Diff.
I tried the 3600 lbs once years ago, which are supposed to be correct for my car, but they made it ride like an empty bedded pick-up truck.
The 2800 lbs passenger side SS springs are perfect for my big block 'Cuda. I do have headers, aluminum heads and an aluminum water pump, so the car should be about 3600 lbs wet.
The handling, launch and ride are the best I have ever had in this car. I do have AFCO double adjustable shocks all the way around.
The thing just squats, weight transfers and hooks up HARD!
I highly recommend the combination.
Here's a picture of the car at full throttle, with the original 4 speed, in 3rd gear with 3.54's pulling away at 70+ mph.......BTW it pulls over 700+hp.
I've since put in a set of Dana 3.73's and a Passon 5 speed. It's downright sinister now! You can feel all four tires twisting in weird contortions as it just dead hooks (once rolling). All I can say is thank God for subframe connectors and Mighty Mount motor mounts. The car is a high 10 second vehicle capable of burying the 150 MPH speedo and wanting another gear.