Ok... so figured this out myself this weekend for anyone else wondering....
I measured:
Stock Zilla arms, 3+2 wheels= 47.5"
Metal tech arms w/ Z400 spindles/hubs and 4+1 wheels= 48.5"
here are some pics....

Metal tech set-up w/ 4+1 wheels on left, stock on right w/ 3+2 wheels


Metal-tech arms w/ Z400 spindle/hub, YFZ450 calipers:


Stock arms/spindles/hubs/calipers: