from a standard form. the t-3 from a saph 4wd is the biggest. it can flow more air then the t-3 of the saph2wd.

the saph cos turbocharger has a bigger ex.house and a bigger comperssorwheel. and the inlet of the comperssionhouse could be bigger. but for the conversion you are building, i think youre better of with the saph4wd t-3 then with the rst t-3 which is to small.

cheers