If it is already there it wouldn't hurt to have done or even be much more money just to have it done. What is also nice is that an 8" wide rear wheel with 4.5" backspacing is a perfectly centered, 0 offset.
Please explain this to a dummy... Why is 4.5" zero offset on an 8" wheel and not 4.0"? I'd sure like to understand this before I drop some cash on the wrong wheels..