I wouldn't put the A4LD behind anything more than a V6! As for the 5 spd, it may be ok but it's questionable. Dependant of course upon your driving style. The fact that you're wanting to drop in a V8 suggests that you like power, much like myself. My '91 EB 4X4 has 182,000 with a Vortech supercharger, Superchips custom chip, Flowmaster cat-back etc... I despise the A4LD, the ratios are too low(numerically) in my opinion. It shifts very smooth but thats about the only good thing I can think of on it's behalf. Whatever you do, just do it right the first time and be done with it.