What class do you expect to run the car and what kind of tree? Does the class permit deep staging? Some "street" classes require factory glass, lights, dot tires, tags etc. Some pro footbrake classes forbid 2 steps and trans
brakes. IMO the ET and 60' isn't important and you really need a dialable car. Doesn't have to be consistant but does need to be predictible. I always hit the same spot on the tree and set the cars up to cut a light. What tree will the class(s) be using (sportsman 500, pro 500, or pro 400)?
I would pull all the AC stuff from the car. Kirkey makes nice racing seats, install a spool in the rear (real posi), 6 or 8 point roll bar for safety and to make the car more rigid, frame connectors etc. The car needs to be able to hook on spit.
'07 Mustang GT 4.6 Auto C&L cold air, 3.73 gears, Diablo tune, and MT drag radials.