Tom -it doesn't sound like a taper if the OP is talking about using the crank pulley bolt to pull the pulley onto the shaft does it?

I am assuming that the nose of the crankshaft is parallel, not tapered.

To be on the safe side for heating the pulley, heat it in a domestic oven set to 100 centigrade.

If there is a seal that runs on the surface of the pulley at the back, lubricate it sparingly with ordinary general purpose grease, so that the seal doesn't run dry when starting the engine.

Better to use an ordinary socket ratchet wrench to wind in the crankshaft bolt and then use a torque wrench set the the correct torque to final tighten it.

Bu then you are going to say that you can't lock the crankshaft when tightening the bolt.

You can try putting the car in a high gear and have someone press the brake pedal, or remove the starter motor and have someone else jam the flywheel ring gear against the casing with a big screwdriver.

If the spigot on the crankshaft is tapered, You'll not need to do anything, The pulley will practically fall on and it will be crucial that you tighten the securing bolt to the correct torque.If it is a stretch type bolt, You'll need a new bolt too.