The axle on the '36 is narrower than the later axles. If you replace the axle you will have the wheels outside of the fenders and will have the tires hitting the fenders. The late kingpins are bigger than the early ones, there used to be available a bushing kit that could be used to adapt late spindles to early axles, but I don't know if they are still available, you could have bushings made to fit.