Who is the best place to go to get new rear leaf springs (the heavy duty hemi type with the 6 on one side and 7 on the other) from? ESPO or someone else? I heard the Mopar Performance ones were absolute junk and would sag a year or two after they were installed since the metalurgy was garbage. I'm trying to give the back end of my car a little lift and the stock springs are just old and most likely worn out.

thanks.

I've bought several from ESPO over the years, never had any issues.
In fact I just bought a set for my new project car.

I can recommend Eaton Springs, very nice product.

https://www.eatondetroitspring.com/

Just bought a pair of the Hemi springs from ESPO, got 'em in +1". Happy with 'em.
383 Road Runner restored street car.
Previous 4.5 leaf rear springs were someone's repros (had previous owner name tag and a white tag with red & blue, too garfed up to decipher) and they were DEAD, bowed up over an inch.

thanks. Looks like Espo is the cheaper pricing plus they are a lot closer to me which will most likely save some $ on shipping costs.

My 71 Super Bee has the 6 and 7 leaf springs (Hemi style) from MP. The previous owner put then in the car in the end of 2014 when he restored it and the car hasn't sagged, in fact my buddy that owned it for a year or two before me has put lowering blocks in it because it was too high. Next winter I'll have the amount of lowering block de-arched from them.
Ron