You will need to have it aligned. Set it to the performance specs and not the factory original. Make sure the shop knows your wishes!

Here are the ones I used from Dazes website:
These specifications are in order of importance.

1. NO more than .25 degrees difference between driver’s side and passenger’s side.

2. +2.0 to +3.5 degrees caster.
NOTE: for cars with Adjustable strut rods. Please attain as much caster as possible using the shims (at least 1.5 to 2.0 degrees), and then use the adjustable strut rods to increase the caster and make the sides the same. Also, please note that the caster difference between the driver’s side and passenger’s side needs to have no more .25 degrees difference prior to the adjustment of the strut rods.

3. -.5 to 0 degrees camber. No positive camber, please. There is no problem having a slight variation from driver’s side to passenger’s side to account for the crown in the road.

4. 1/16" to 1/8” toe in

 

consider this approach...

http://www.mustangsteve.com/tierodbushings.html

 

The bushings do not change or improve the geometry, they merely shim a Mustang OE outer tie rod's tapered mounting stud such that it will fit onto the steering arm of a Granada spindle. Using a Granada spec outer tie rod does the same thing on manual steer applications. CSRP's 65-66 specific spindles yield OE correct steering geometry which eliminates the tow adjustment and bumpsteer problems associated with using salvage Granada (or 68-73 Mustang) spindles on 65-66 Mustang.