Thanks Blaze, the most helpful pic I found was an 18rg pic on this site of a white '77 gt.
Yes we have an assortment of air pumps but not the stuff that goes with it. We found a guy who was willing to lend the tubing and stuff to us but then he went on holiday.
The engine is going into a '77 celica.
The RWC guy on the phone couldn't tell us waht we needed as they didnt know, so we might be able to get by without the air injection. I've also heared that not all 18rgu's came with air injection. If anyone has heared any different, please let me know.
I've since found out that the big ugly valve on the top (looks like an "outer vent control valve" but is rigged up like an electric version of a mixture control valve) is connected up to an emission control computer, not what I wanted to hear as they were all left in Japan.
We've figured out how it works and will be chasing up a vacuum switch from a hiace that breaks the electrical circuit at around the 400mm/hg mark. That should run it and look original. They were also in some RA40 celicas (according to Haynes manual)