Just put an a14 in my 1200 ute but need manifold to suit my exhaust ( 2 pin not 3)

Go to genie headers (http://genieheaders.com/) they can custom make them and send them to your door..

Myself and 2 mates had them made up..

We had them made up for a12 and A15 they are 42mm primary pipes.. 4-1 headers or can be 4-2 into a join or straight..

let them know how you want it and they can make them up.. great welds run nice fit perfect and sound awesome.. cost me $350.00 delivered

Or if your exhaust itself is just not able to fit or the bolt pattern incorrect cut the flange off and weld another one on.. or take it to an exhaust shop and get them to resolve it..

will it matter what carb I have on it?
It's standard atm but I do want to put a single webber on at some stage

It won't matter if you keep the original Hitachi carb.. but if you want to put a side draught or twin side draughts on just advise them and they can make the difference on the header flanges as the manifold itself is a little larger and the flanges won't fit correctly between the extractor flanges..

I have some stewart wilkins extractors on my mild a12, which has an oval port head, i find them rather nice...

Just a quick note to remember if you out extractors on you will need to retune your carby as the extractors will effect how it works