There is a lot of advice out there against getting wheel spacers vs getting new wheels with increased backspacing. What's the difference on how it affects the suspension/drive train? Both equally move the tire away from the truck and should produce the same amount of increased moment arm. Is this yet another one of those "I've heard it so I'll say it" things, or is there actual data out there. Thanks for any input.

 

Actually wheel spacer = DECREASED backspacing:
- http://www.4crawler.com/Diesel/Tires.shtml#WHEELS

As far as the suspension and steering geometry go, no difference in say a 1.5" wheel spacer and a wheel with 1.5" less backspacing. Spacers do have more potential for failure, 6 extra lug nuts, 6 extra studs. It is also harder to check, as you need to pull the wheel off to check the nuts holding the spacer on, vs. just checking the wheel lug nuts for tightness. I have run both spacers and wheels with less backspacing (2.5") and have had no issues with either setup.