Decades ago, I bought a truck with long shackles, stock springs. Then I bought 33x12.5 tires, and I rubbed the treads the first day I took them out. The spot was where the tub does a 90-degree turn behind the front seats; I immediately did some damage to a fresh set of BFG Mud Terrains. Then I did a 2-inch Rancho lift with longer shackles, I still had problems rubbing. I was really pushing that vehicle; I was in my early twenties and in need of all-kinds of lessons. I wasn't running much weight, no doors, just a couple of loops for a roll cage and bikini top. The tires you mention are narrower, and I was using an 8-inch rim, iirc.
Yes, the stock springs will be a softer ride, they are arched less, which helps. I'm currently using OEM shocks and springs, with 215-75-R15, with less than 28-psi. I'm really happy with the ride like this, but the truck, as a project, looks kinda derelict, which I actually appreciate a bit. Paved-road irregularities in a spring-under-axle 40 have always been nerve-racking, compared to anything else I've been in.
Yours has a proper appearance. Changing to stock springs, with longer shackles (anti-inversion-type) requires shims and longer sping pins to correct the angle of the spring perch, both front and back. A somewhat vertical shackle angle tends to resist flexing, or at least that is my impression
Hence, "warranted" - meaning deserved, or necessary to match those tires with those springs. How much are those treads inflated?