In 1994 if you got a manual trans, it was a powerstroke, if its an automatic it came with an IDI turbo.

it is actually very easy to tell the difference by opening the hood:
powerstroke has the air filter on the driver's side inner fender.
powerstroke has no steel lines or injection pump on top of engine
powertroke has a fuel filter housing sitting right in the centre of the motor.

IDI turbo has a square air filter box in the centre of the engine with a hose going to same place the older 7.3 IDI n/a engines did.
your oil fill will be in a front timing cover(rounded aluminum thing), injection pump is mounted in this cover also, 8 steel lines running to all 8 injectors right on top.
fuel filter/housing is on top of the passenger side rocker cover.

I'm a diesel guy and have owned driven both of these engines.
both have their good points.
love the IDI turbo engine for its "off idle" torque, the turbo only pushes a little boost.
the powerstroke is a good motor, but not quite as good the first year as they used the EEC4 computer system. 95 -2003 were much easier to communicate with/diagnose problems.

for low speed/offroad/farm use the IDI is better I think
for everything else the 7.3 powerstroke.

I've seen a 2000 powerstroke over 800,000km on it torn down and show almost no wear at all.

I don't think I have erver seen an idi turbo over 400,000 without being rebuilt.

if its a powerstroke CHANGE YOUR OIL , they won't put up with dirty oil for long!

cheers James