Bicycle Mechanics - Worn out Campy cranks?

My track bike has been making a funny creaking noise in the crank/bb area the past couple of days. It happens at pretty much the same point of rotation, almost only when im putting pressure on the cranks. I tore apart my bb today and repacked it, same noise. I have a set of what appeared to be lightly used Campy strada cranks on it with a Miche bottom bracket. My friend suggested that the taper on the cranks might be worn, causing the creaking. Is that possible? Any other ideas?

It's possible, but the culprit could also be the pedals or the saddle.

Its definately not either, becuase i can put pressure on the cranks with my hands and cause the noise to happen.

how far the cranks sitting on the axle? are they bottomed out? if they are, then they are worn.
if not, take them out and clean both tapers on the cranks and BB axles.
Also check if there are any cracks around tapers.
When putting back, don't put grease, just oil.

I just tore it apart and put it back together yesterday. The drive side arm seems to be pretty well near the bottom bracket, but the left side(which as far as i can tell is where the noise is coming from) looks normal. Ive heard something about using plumbers tape on the threads of the bottom bracket to get rid of noise? My bb's old anyway, so should i just invest in a better set of cranks and a new bb?

yes, and you should give me your old cranks.