Moyer is your friend, things to do before you slide it in there:
Electronic ignition kit
Retrofit alternator with Moyer's beefier one, (Hey, VW canceled Motorola in frustration).
Fit the oil change kit to the pan fitting on the engine's port side
her with Moyer's electric fuel pump
Consider fitting new trick motor mounts that have fresh rubber to keep her quiet
Check the exhaust
elbow, probably ought to be new
Buy some Marvel Mystery oil to add to the go juice and keep her valve guides happy
Any money left?,put the oil filter kit on...
Hire the engine guy that has the laser alignment kit to help slide her in
Enjoy the smooth quiet of an A4 loved and happy....
Oh and another thing, just about everyone around here adds the plastic coupling to the shaft which helps mitigate the alignment problem and protect the engine assemble in case of grounding, line
wraps and the like.