Low oil pressure just trashed my engine, I think I'm gonna go with a replacement since I don't have the time to rebuild it right now. Does anyone know that all the options are as far as what will bolt in to my '01 A4 1.8T Quattro automatic? As far as the other B5 1.8's and what VW 1.8T's will bolt in if any? Also, will the 2.8 V6 fit by any chance?

 

Any 06A block from a A4/Passat automatic will work. Yes a V6 will work but then you will need to replace the engine harness and ecu for that engine.

Your best option is to just find a working 06A short block and swap it in using your stock head and the rest of the parts off your engine.