anyone ever done this? its a 89 model (older body style) 1 ton 2wd truck with IFS tbi 454 and sm465, and its soon to be a straight axle 4wd. what all will have to be changed or replaced on the front. i already have a dually 60 front and 70 rear both with 456 gears, 32 spline sm465/np205 with crossmember and shifters. im not concerned with the trans and case as i have done this before, just needing info on the front axle swap.thanks for any info!