I need help

[Al 29Tudor]

I'm installing the rear brakes on my 29 Tudor and can't line up the front end of the wishbone. Does the car need to have the weight on the axle or the jack stands under the chassis? The misalignment is out about 1/4 of an inch on the right side - left side is in. It looks like the rear end has to move back to get the bolt in the front end of the wish bone.
I really need help on this.
Thank you much.
Al Leach