Got 3 questions here: Looking to replace the 40 yr old leaf springs on a 318 e body. I see summit has a good price on lowering leaf springs (95 each) or even the heavy duty set (105 each). Anyone have used the lowering set and do they recommend them instead of the standard (or heavy duty)? If you recommend to not use the lowering set, would it be better to go with the heavy duty set of standard set? Third question, I see they have the prothane shackle kit at a good price as well, any good or bad here?

Thanks,
Mark

Go through ESPO for the springs, and ask for them to be de-arched. You can use the springs that are on the car as a guide to figure out just how much. Mopar Action did something similar with their Dakota project recently, I'm sure you could get the back issue.

As far as shackles, Mopar shackles weren't the crappy auto zone pieces that you find today. I believe Just Suspension sells shackles that will fit your needs and won't skew. Their new website is crawling or I would give you the pn.

If you get everything and decide you need a bit more drop, you can flip the front spring hangers. JS also makes a 3 position adjustable shackle set, but it may not work with your rear valence, it's a tight fit.