Caster Question

[C4 Pazzo]

My 2000 C4 Cab has tracked to the right since I bought it in September (not a hard pull, but a definite drift). After installing the RoW M030 and getting it aligned, it has improved, but still drifts slightly right (not just due to the crown in the road). Normally, I wouldn't do anything about this, but I tore the ball joint boot on the right control arm when I did the M030 install (next time I'll use a decent ball joint extractor). So, I think I have three choices:

1. Do nothing - Put some rubber cement on the boot and replace the control arm if/when the ball joint goes.

2. Put in a new series control arm now - cost about $260 plus new alignment

3. Put in a service control arm with adjustable caster eccentric - cost about $540 plus alignment.

So, what would you do? Would you seize the opportunity to even out the caster? Or would you wait and see what happens? Is 1/2 degree of caster differential enough to cause this tracking? If you went for the adjustable control arm, would you install it on the right side, and match the 7.55 deg caster of the left side, or would you move the left arm to the right and match 8.04 deg (assuming swapping wouldn't change the caster)?

Any thoughts appreciated.

Here are the alignment stats:

Front caster (Left/right) 7.55/8.04 degrees

Front camber (L/R) -0.37/-0.44 deg

Front toe (L/R) 1/32" 1/32"

Rear camber (L/R) -1.24/-1.17 degrees

Rear toe (L/R) 1/32" 1/32"

Thrust angle -0.01

Secondary Angles

SAI (Left/Right) 17.44/18.76 degrees

Included angle (L/R) 17.07/18.32 deg

Setback (Front/Rear) -0.13" 0.39"

Track Width Diff. -2.73"

Wheel base diff. -0.52"