Axles that can be swapped in place of the stock axles

Quote:

Originally Posted by Swampthang

They used a '85-'96 Ford dual rear wheel highpinion D-60 front axle and it is a direct spring-over bolt in for our trucks. Measuring at 77" + or - it works well with surplus Humvee wheels on M trucks..

Can someone help me understand what the OP means by dual rear wheel high pinion d-60 front axle? Is that a front wheel dually? I bought a d70 thinking it was the right size (GMC 3500 ) but it's only 71 wms to wms. So I'm trying to find the right solution for the frontend assembly and am too inexperienced here to follow the terminology. Appreciate the help!