floor levelness

Besides floor levelness from right to left, should you measure levelness from front to back? If not how will this affect ride height rake?

Also with string setup how does one compensate for tires/wheels of different width in front and rear of car, staggered? Can you just use a different point on the car than hub to measure for squareness?

Ideally the floor should be level in all directions, however for our purposes it's more important side to side as this will have a major impact on your camber readings. Obviously you don't want to set up on a hill, however if the car isn't perfectly level front to rear the impact is quite minor in terms of setting camber and toe. The exception would be if you're corner weighting the car in which case we do need to be perfectly level. If you want to level the patch front to rear you can apply the same techniques I use to level side to side.

The effect of different wheel widths or track widths front to rear is compensated during the set up of the strings. We aren't looking for the same measurement on the front to the rear but rather we want both measurements side to side at the front to match and both measurements side to side at the rear to match.

Thanks for the clarification.