for my point of view, you can transplant the turbo engine in your quattro car.
But, you need also to transplant the engine wire, and the ECU.
good lucks ! it takes at least 2 week ends.
for mechanical side point of view, no problem, you can keep your 4WD gearbox.
which engine did you get ? MC, KG ?
the MC is 2226 cm3 and has a catalysator, 165 HP
the KG is 2144cm3 no catalysator, 182 HP
the 1B is 2226 cm3, no catalysator and 200HP
on the KG, you have no boost pressure regulation, piloted by the ECU. On the 1B and MC, you have.
on the KG, you can easily boost the pressure to 0.9 bar. Be careful, at 1.0 bar, the ECU cut the fuel pump. YOu can find on the web some moutings to take over this regulation.
we want to see the pics of your transplantation !!