The factory drain tube will work with all 3-bolt turbos up to the PT76 GT-Q, but you will have to drill out the flanges' bolt holes for the larger bolts that are used on T4 series turbos. Typically we would require a -10 AN size return line be used on all turbos, with no kinks in the braided SS, no cast steel or aluminum fittings, but all hose ends and straight adapter fittings. Anytime a kink gets in the braided hose, or if cast 90* or 45* fittings are used, the oil can back up in the turbo and flood the cartridge to the point of leaking past the oil seals.
-4 AN feed line and -10 AN return.
HTH
Patrick