Straight axle versus twin I beam
 

I have a 1986 f 150 4x4 with twin I beam, And I just recently purchased an old 1977 ford ranger 4x4 . Does anybody know what modifications would have to be made to swap the front axles. Would rather have the straight axle over the Twin I beam.

I remember reading about a very large stamping press ordered by Ford. It was designed to stamp out the twin 'I' beams in steel ... the steel stampings were to replace the heavier grey iron forgings that the Twin 'I beams were constructed out of.

All this to save about 20 lb per truck for better gas mileage.