Hy FusionFanatic, welcome, your truck is actually considered a one ton, with a GVW of 8800 lbs.. You are correct about the ability to swap complete differentials with lower (numerically) ratios from newer trucks with automatic transmissions. As far as I am aware there are no "kits" available containing all the bearings and seals required to overhaul the differential and I don't think the crown and pinion are available new. Good luck in your quest, please keep us in the loop on your progress.
I have had this truck for 2 years and been calling it a 3/4 the whole time! good job its not that different when ordering parts! Thanks.
