[HummerMann]

Hub spacers and adapters are never a good idea. They cause vibration from imbalances, they can fracture, and they put added stress on the tire threads and those are ones that meet SEMA standards, the others are worse. As for 40" they are GREAT offroad and in the mud, and they are loud, rough and a pain on the street. You will definitely want to lift it, if you go 40s, and that means regearing and over 100 threads to look through in the tech sectiion for resolving problems, such as the stearing toe in and drive shaft set ups. Big tires look cool, but if you don't drive offroad a lot or show your machine at shows, they are not easy to live with if you drive it a lot. IF you don't regear or supercharge, you're going to loose a lot of performance.