If it helps, I am on a T3/34.48(T3 comp housing machined out, T34 trim), slightly mod to inlet ports, run 17/18 psi, for 300bhp, I run greys on mine and a RS500 cooler, act's range from 60C, to a few above ambient, note 60C is after soaking heat after being left 1 hour, but within 1/2 mile dropped drastically, my bhp is mega accurate on rollers that are regularly recalibrated as needed, and re gripped.
At a guess I'd say your i/cooler will be fine at your present level.
tabetha