Hey Slowy
If i had your rig I'd be looking at the the SuperDuty T5
http://store.summitracing.com/partde...5&autoview=sku
or
http://www.fordracingparts.com/parts...tKeyField=1879
Eagle Auto Parts in Dandenong is the local Ford Racing dealer although I haven't used them in that capacity before.
http://www.eagleautoparts.com.au/
Might be cheaper to purchase from US (who knows)
Thats if you cant pick up box locally at a good price
LoBelly