For a long term solution, I dont like the idea of the T3T4 adaptor. I think I will loose exhaust flow capacity and may get increased exhaust (header/heads) temperatures due to reduced exhaust flow.
Although these are ceramic BB turbos, i think i would loose some spoolup due to the restriction.
I think that i should consider a turbonetics T66 with ceramic BB and large shaft. (actually slightly cheaper than the GTK).
89 930 Cabrio , (soon to be for sale.)