Safe to use Wheel Adapters 5 on 4" to 4.5"?

You don't ever want a larger rim in the front and I wouldn't use cheap spacers if your making any power. Plus it may fail inspection if y need that. I may be wrong but someone may correct me if so Dr diff sells replacement axles. Think around 200$ each with bearings and plates. You will have to change the backing plate and drums tho. That will also change your bs.