Stock rear suspension question

[Greg63]

Okay, here is the scenario;
I just replaced all my front suspension - everything from the front crossmember to the tie-rods-I mean everything. I had the front end fully aligned professionally from a recommended shop and it rides and tracks great. It is all stock and now new.

The guy who did my front end alignment noted that there is a difference in the rear suspension; + 1/2 a degree on the drivers side and - 1/2 a degree on the passenger side.

What does that mean? Today I measured from front tire to rear tire on each side and found that there is a difference of 3/4" from one side to the other on my wheelbase.

Now I know that there is no adjustments in the rear suspension, and I bolted the front crossmember into the only holes that were in the frame and there were not any oval holes for adjustment.

Any idea how to true up the wheelbase to get it close (add distance on the drivers side and subtract distance on the passengers)?

Greg