you need 25psi of boost to make 250bhp,i would say thats a tad much for that bhp,youd prob make the same bhp with a tad less boost with a less restrictive exhaust
its not all about top end bhp,same applies to the full rev range
also at which rpm do you make this bhp,would prob push the power up the rpm a bit more
still if your happy,then thats what counts