They are only little buggers mate, not real flash for anything over 2 litres and even a 2L will be stretching the friendship...
But for what you want you'd have f-all top end and all mid range.
I was under the impression that RB20 injectors were 270cc and RB25 were 370cc. But these are 370cc RB20 injectors? If they are Jeff I might have to talk to you again. This is Jay just so you know.