[steves1967]

I'll assume that the rear sits higher than the front. With that in mind I think the easiest way is with a new set of leaf springs. There are a few companies that sell them over the internet, but the best bet is to find a local big rig truck shop, they should be able to fix ya up. You can add lower blocks, but I shy away from those as they tend to and more leverage against the rearend.