No, I don't think you do. I have never went that direction on swapping them out, but I once had a Ruger Bisley 44 mag, and I did not like the Bisley hammer, so replaced it with a regular Super Blackhawk hammer and it was a clean swap out without issues. The only thing is there was a little gap if I remember correctly behind the new hammer in the frame, but it was not a problem.
I didn't like the Bisley hammer because it rolled down a lot closer to the backstrap when cocked and under fast shooting, my shooting hand would slip up just enough that I couldn't cock the hammer with my off thumb without having to reposition my shooting grip. The taller regular Super Blackhawk hammer solved this problem.
I feel sure you will need to relieve the frame or grind the hump on the Bisley hammer to install, but I have never tried it.