Installing Harmonic balancer with crank pin

[just]

I'm trying to put my motor back together after tearing it down to swap out the cams and I've been stuck all day on mounting the harmonic balancer because I cant get the pin slots on the pulley and the crank to align. I've had to pull it out and try again because Each time I push the pulley on to the crank to where it aligns with the pin slots and start installing the balancer the pin slots will be off half way down the way. How does every body else deal with this? Please leave any helpful advice..