I go with Bastian.

A PT to PT swap is done in a few hours, a converstion can take days.

Get the PT engine and get the car on the street,
if yo still want to make it faster () yo have enough time to find all parts for a conversion.

Gude Mario Audi 100 CD Autom. Bj.83 Audi 200 20v Bj.89 Audi 5000 Bj.85 Audi V8 3,6 Autom. Bj.88