A4QuattroV6

I am going to buy a 2001 Audi Allroad 2.7t Tiptronic with a bad transmission. I am looking to use the good transmission from my 1998 A4 2.8 30v Quattro Tiptronic. I am aware that I will also need the rear diff to maintain final drive ratios between the front and rear axels. I am also aware I may need to have it coded. Are there any other issues that could prevent me from doing this?