For 2008 the ambulance prep pkg included:
diesel engine
dual altenators
wide track rear axle (regular width optional)
AC
front tow hooks
roof clearance lights on SRW (std on DRW)
telescoping trailer tow mirrors
elevated idle conroller (SEIC on 2008, but 2001 came with auxiliary powertrain control module = APCM, a.k.a. auxiliary idle controller or AIC)
Probably the same for the 2001 model.
IOW, nothing you can't order on any new F-350 DRW pickup except the wide-track rear axle.
If you have the idle controller but no manual, here's how to get the manual:
https://www.fleet.ford.com/truckbbas...pcm_manual.pdf