The original axles were mounted above the springs. If you mount the replacement axle under the springs, you will have a serious "down-hill machine."
I am really hoping your 2.73 is a typo for 3.73.
I don't think you need to reverse your springs.
I welded the axle perches sold by Classicparts to a 12 bolt GM axle (3" tubes). They have an extra hole way off-center for the thru-spring bolt head, which locates the axle in the original front-of-center position.
Unless you plan on using giant tires, this location will work for you, and look more original.
Carl
