Still working on my 1950 Shadow and placed an order several mos ago for new cams as the originals were pretty worn. Mark 1's would seem to be the appropriate type should I still adhere to original fitment. However, there has not been availability within the spares co for Mark 1's as of yet and "there are some Mark 2's on the shelf". Comments and recommendations as to what to use would be appreciated. I've heard the Mark 1's are a little more fierce in opening and thus a little more powerful (and noisy) Thanks in advance for your individual thoughts.