Im having 4x4 Cossie with T3 running 1.3 bar peak boost pressure, green injectors etc. Im not sure whether I have stock clutch and head gasket, they could be original since I would only have about 300 bhp at the moment? Is there a point in upgrading into Escort Cosworth T34 (.63 A/R?) turbo? How much more power it would give with same 1.3 bar peak and what are the chances for my drive train to handle the extra bhp? Would it just be better to up the boost with standard T3, or is it on the limits already?

Im relatively new to turbo technology so any help is appriciated.