I dont know if you have drove a truck of this age lately but if you could i think it would help you figure out what you want to do. The rear end from the 84 is not a just bolt in deal and it is wider than your old one But it will be under a wide flat bed so it wont matter.I have lived with only haveing a 45 MPH rig and i didnt mind but thats me. On my trucks i never wanted tire slideing front brakes so you could live with you front axle with a diffrent rear axle and a brake booster and have all the brakes you need. Just my 2cents.
