[farmtruckIII]

Ok here it is, if the truck is leaf sprung any rear end up to 87 will work, exept for one minor detail. The right rear shock mount has to be flipped from one side of the axle tube to the other, because 73-87 had staggard shocks. You can also just replace the axles all 12 bolt trucks use 28 spline axles. If it is coil sprung the axle swap is the easy way out, unless your good at fabrication work. I have done several of these swaps, my 70 step side has the original housing and 78 axles, my friends 72 GMC has a 2.73 one legger out of an 87, and my 71 gmc has a 3.42 posi out of a 72 van. If you need help with the swap I am more than willing to lend a hand.