Holy shit dude. How did you figure these numbers? Did you bolt each leaf to a plate and gauge them by weight? You did a lot of work here no matter how you cut it.
I did recall an email I got from Don on this exact subject. I just pulled it up. I don't know if anything was meant to be confidential so there are things I won't mention, but he said the factory PW leaf rate is right at about 275 lb/in. He told me the rate his long travel leaves run as well as a comparison but I'll keep that to myself. Remember that leaves are progressive and the heat treatment, length and thickness are used to achieve rate. Those calculated numbers are way too high. If we consider the rear axle to have around 3400lbs (I'm guessing) that is roughly 1700 per spring pack. Assume you have to compress those leaves by 8" to get ride height, then consider that leaves are progressive, your base rate is way lower.
This is not at all to be a buzzkill, and in reality doing the swap you suggested may actually work out perfectly! Since the parts are free, why not try it?
Sent from my safe space