I have a 4x4 saff with 400bhp and was thinking of taking it to over 500 with a T-4 ect because i really like top end power.
It has grey injectors and fully ported head, long stud and all the usual.Im thinking of doing the work myself if poss and then having it dynoed and mapped.

Basically im just trying to get a rough idea of what extra work will need to be done to the engine.And of course what box will it need bearing in mind it wont be launched.

Cheers for any advice.