The worst problem with using the wrong width wheel is too much crown in the tire contact surface. If the tire crowns too much you don't use the available amount of traction from the tire. You will be able to see where the tire does not contact on the outer edges of the tire.
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88 347, Twisted wedge heads,Comp Cams 224/230 cam, 1/4=10.516 @ 126.27, 60' = 1.446
http://xs-fx.com/raughammer/larrysample.htm