My mate is hassling me over what turbo to get for his 2.1 ZVH lump...

Now I've told him the best way to go is to get a stage 3 T3 but he's adament he wants big power (its on standard Zetec rods and pistons but he won't listen ) so is talking about a Cos T3 or T34 to get him 260bhp or more...

Please someone give me something technical I can throw at him so he leaves me alone for a bit!