[JSeery]

For starters think you are going about it backwards. I would mount the wishbones on the axle first, then the spring, then install the spring/axle onto the frame and then attach the tie rod ends at the back. You have to check the angle of the axle kingpins and adjust the castor after it is installed. The castor is adjusted by turning the tie rod ends in and out and re-installing them. You can not make much adjustment this way, so if it is off you will have to use some other methods to get the correct castor, but you won't know until it is all installed with the proper weight on the axle. The spring should have a square bolt head at the top that goes into the square opening in the crossmember. If the camber alignment is off the correction is to bend the axle, the caster can be adjusted if required and toe is set with the tie rod adjustments. There is not a front or back to the axle.