Well it depends on which hotside it is. If it's a gt55 you'll go tighter on the a/r than you would if it's a GT47 because the bigger wheel will allow you to. If you are going to a bigger housing because of drive pressure issues I don't think you will solve your problem. The wheel is the restriction, the housing just dictates where in the rpm band spool happens. I think that is the key to these limited size combos. Big wheels, tight housings, so the spool happens early and you can use your power management device ( ams1k ) to put the power down like you need it.