Happy New Year to all.

I am planning to install new leaf springs on my 63. Ordering them today from Dearborn Classics because they dropped the shipping charges for January.

My question is: How can I keep the rear axile in the same place? Will it move one way are the other during installation? Or will it install back in the same spot front to back? I do not want to be going down the street out of square.

This will be my first leaf spring install,
Thanks