Time to change cam?

cheers, Ramcharger, the warm beer here is good!
Moper, i think you are probably right. I just checked my current cam card
lift .462 & .470
duration @ .50 218/224
So, not a huge difference. However, the next cam in the voodoo range seems to be quite a beast.
My usual rev range is up to 3,500 and occasionally racing up to 5500.