Changing the spindles did not likely change your caster any, but the camber might need a change.  You can shim UCA bolts evenly front and rear until you get zero camber.  Do the camber adjustments first, then the toe.  If you use equal shim changes front/rear, it will not change caster.  A carpenter level is fine for this job.

Install the tie rods into the adjusting sleeves, evenly threaded until they are about 1/4" from touching each other.

Install pitman arm and idler arm and center link.

Center the steering wheel.

Adjust R&L wheels until pointing straight ahead with steering wheel centered.

Take measurement in front and in rear of front wheels at approx mid height of the tire.  Set toe in at 1/8" (1/16" per side, so the steering wheel stays centered.)

Do this and you will have a better alignment than you can buy anywhere.

Aim for these specs:
Caster (zero if stock, not lowered) 3 degrees each side for cars with Shelby drop.
Camber zero
Toe 1/8" toe in.