How much is really different? Will a sprint spindle go on a midget axle? I was told yes but want to verify before buying new front axle..... Thanks

My midget kingpins are smaller diameter than sprint kingpins by nearly a 10th of an inch

Bummer.... I have my complete sprint setup like new collecting dust and wanted to use them on my d2. Weld magnums with rotor and everything.

are you talking lightning sprint or full size?

Full size. The parts are for my 07 comp welding non wing car.

The kingpins are definitely different. Midget kingpins are 0.813" (13/16") and sprint car pins are 0.859" (55/64"). I believe midget spindles are patterned after early Ford (Model A?) parts while sprint car spindles are based on mid-60's Ford Econoline van/pickup units, though racing spindles have 10 degree inclination while OEM parts are 5 degree.

Why don't you just see what you have, some are the same, some are slightly different, and some are totally different, the bolt on arm patterns are different, the king pins, some are the same, depends on what manufacturer you have, and how old they are, midgets usually have 4 bolt holes for arms on them, sprint cars typically only two, until you actually take them apart and see what you have, it's just so many words wasted. Bob

3.25 arm spacing vs 3.75/.810 Kingpin vs .856. If hubs are for straight and not stepped spindle, then hubs will work with midget spindles. Most midget brake mounts are for 10 to 10.5 rotor. Some sprints run 10.25 rotor, but usually run larger like 10.75 to 11". Sprints can run larger rotor because they run a 15" wheel vs 13" midget wheel.