will probably be on the side, the injector has a 1 way valve so ends up being about 50-60mm long then the 1/4" pipe comes off it so would struggle for room and pipe angle underside.
hoping to get a new filler for the tank in the next few days, ordered a few more parts off ebay to complete the install, the 'full tank' led turned up and some dark grey acoustic carpet. also 'forge' boost take off came through but have to say it looks like copy tat, the seal is now a cork gasket not an O ring as shown on the website.
also got cheapy digital boost gauge on the way so i can keep an eye on boost levels, had to be digital so it can be easily read - i'll be mounting it out of direct sight.