v band, make an adapter for about £30 if that's what you need, in fact i have one i made from my old one on a 5 bolt, dead easy.
wilky is his username on here, also bernies turbos or something very similar on facebook.
when i was looking, he suggested making up a T38 with a housing from this and machined out comp housing, bigger wheel and what not with 360 bearing for £550.
that's what he does, makes turbos and rebuilds, very helpful even though i didn't buy one from him.
the GT3071r on my setup is an animal, only running pansy power though at the moment (20psi) as i've swung cams to make better power down low and traction is an issue in wet weather.
i've had it at 1.8BAR and that is really pulling hard then.
a T38 will pull well, just a little laggier.