So this is a bit of a dumb question but I'm looking to replace my rear leaf springs and I can't find if the Dayton P/N 431503HD on rockauto is a single leaf pack or a pair of them.. has anyone bought new leafsprings for their truck and did you buy quantity. 1 or 2?

I'm also looking for other options as well, running a cap and heavy storage drawers in the bed full time, I'd really like some heavier rate rear springs and possibly enough lift to remove the rear blocks with a slight T-Bar crank.

Relatively recent photo of the truck in question for attention: