Yep. Many years ago.....(here comes the boring story).........

OK I will shorten it up. I went after that at one point.

Chrysler's Mexico spring plant KNOWS how to make leaf springs. I've had a couple Rams with 200k + miles on the original springs
and no problems. Plant Engr defended their process, even pulled several from production to prove
they were making MP springs to print......This was true....however the prints allow way too much variation, and don't
get detailed enough to make as consistent a product as I would prefer.

I'm not going to say exactly what information is missing from the OEM stock replacement XHD spring prints as well as the SS prints, but
it was substantial in that there was just not enough detail in them.

I tried but was not able to get an MP engineer on board with an addendum or alteration to the '60s specs. I think he had bigger fish to fry at the time.

The MP springs are hit and miss, and that's not going to change.
The SS springs on my car were reworked by a local spring shop and that's probably why they have not sagged out.

It'd probably be a better story to tell over a couple beers, tacos, or both.
I forgot to contact you the one time we went to Myrtle Beach, remembered on the way home, and was mad at myself for a couple days about that.