G-Auto*Hero

i was wounderin if you can down size a turbo from a t5 to a t4 on the hot side????? i had a chance to buy a turbo hella cheap for my build im going for 600hp b16a. its a garrett .70 A/R and 1.25 on the hot side, is there a turbo manifold that i can fit that t5? it seams that im going to have to make a costum flange for it. i dont know man???? im thinkin of trashin it