Thanks for the pictures. Those cars are way too low than what I am going for!
I don't think you're going to be happy with stock ride height springs.
This is what BRAND NEW stock XHD Mopar Performance leaf springs looked like on my Challenger the day I installed them and many claim they will settle/lower even more.
This was not acceptable, I immediately removed them, (didn't even drive the car) and took them back to Summit Racing.
These XHD springs are the ones that factory HD 440 Six Pack Hemi cars came with.
Remember these are meant for 14" factory wheels and short bias tires and if you look at pictures of these cars when new, they sit very low in the rear(lower in the rear than in the front like stated above)
My rear tires are 275/60-15 and are taller than yours so my rear tires do go up into the quarters more.
After suggestions from Mopar suspension expert DR. Diff I ended up going with lighter Mopar Super Stock springs from an A body(Dusters, Darts, etc.)
This gave my the low, (but not too low) ride height I was after with a softer riding spring that was still a race spring for when I take the car to the dragstrip.
My suggestion to you is to lower the front torsion bars and wait until spring so you can drive it and let everything settle.
I've found that lowering the front ride height a bit actually lowers the rear a small bit.
If those are Super Stock leaf springs on your car you also might NOT be happy with it's stiffer ride.
After driving it for awhile determine if your happy or not, if it's still sitting too high in the rear figure out how much you want to lower it.
If your happy with the ride and only wish to lower the rear an inch or less you can replace the front leaf spring hanger mounts with ones that have 2 mounting holes.(see pic below)
Using the bottom hole will give you stock ride height, using the top hole will lower the car about an inch.
If you think you want new springs I would suggest the ESPO springs (stock height or +1") from Springs and Things over Mopar Performance springs.
I would still get the suggested front spring hangers with the 2 holes so you can fine tune your ride height +/- 1"
I would search here for pictures of Cuda's with the same rear tire height as yours.
Good luck and beautiful 'Cuda...love the color.