That depends on the plenum. there is no universal rule. c&l 75mm, accufab 70mm, trickflow I think flows best with 70mm can't remeber what the dragon worked best with.
injectors will hold up to 300hp+ so you should be fine. the best I have seen with all bolt on's including cams, bullit intake, and everthing but the kitchen sink is 300 on the nose. rule of thumb I have heard is like 315hp+. basically I would consider injectors if I was running, heads, cams, longtubes, intake the whole nine. it is a point that I am sure could be debated.
ok good thats what I thought for the injectors but I was watching that show "tuner transformation" on speed channel and they were ricing out a civic and all they did was a CAI, and full exhaust headers back, and they upgraded the injectors.....just made me wonder....but I guess they are a bunch of morons on there...
yeah I know 0 about honda's so I don't know why they would need injectors for that. 2 liters = cola where I am from so I have never bothered learning abou them.