dont know about fitting new engine but i do know about 1.9TD ducato gearboxes and that is that the parts are almost impossible to obtain, fiat main dealers are asking 189.00 pounds for a part worth 39.00 pounds making it uneconomical to make repairs, someone once stated the ducato gearbox components are made of cheese, that may sound silly but it not far from the truth, the early ducato gearboxes are an embarrassment for fiat and they wish they would all disappear