I got a bargain 1977 Z1000 airbox off US evilBay: as was informed it will fit straight onto the A4. Its in nice condition and oddly for eBay was a real snip: costing a staggering $49



But there's a strange appendage / breather on the top front face of the Airbox: dont recall that on the A4 so was simply going to remove and fit a blanking plate - unless I am missing something obvious ???
Cheers Tim