one ton axles - compatible with 3/4 ton?

[crosby]

Hi guys. I bought a 79 GMC SRW one ton, and wonder if I can use the blocks from the rear and the front springs in my 87 V20 (with late 70s frame and running gear?). Are the one ton axles different, I have heard they are spaced differently, and the spring pads are in different locations (both front and rear or rear only?). I think the front springs are 4 inch lift (or rearched). Would the front axle (dana 60) simply bolt in to the 3/4 ton? Thanks very much for any help!