I think a good description of the negative of extremely wide wheel spacers and wheels(in fullsize cars) is that the scrub radius is thrown way off. Instead of the front tire contact patch having an a near effortless pivot point along the king pin inclination line, it is forced to be dragged in an arc. But that's in extreme cases and like you said, those negatives are made up by the positives that it provides in this specific application.
G'day mate, I don't know if you have mentioned to people out there, when I packed grease in my EAT14 diffs the other day, some drop kick put double sided tape on some part and put it on the drive shaft as well, covering the shaft which would have restricted it some what, I cleaned it of with acetone and eucalyptus oil, don't know it you're heard of eucalyptus oil (made from the trees) it's brilliant for removing sticky substances, take care, Peter from Australia
I didn't do the spacers but got wheels with a half inch offset instead. I actually love it and my truggy still whips corners plenty tight enough thank goodness.
In a race condition, widening an RC car at the hex increases stability but removes side grip. A wide front with a narrow rear will take away front grip and give a little understeer. A narrow front with a wider rear will increase steering. More details can be found at: www.davebstevens.com/off-road
