Yes they will. The 500/550/650 cams swap pretty well, and I always would encourage you to find the matching rockers when using a used cam. Pay close attention to the lobes when buying a used cam, and only buy it from someone you might actually know, or can get a vouch for.
I've bought a used one, was promised it was good and reliable. Upon receipt, it was worth nothing more than its scrap metal. If you can afford it, I'd rather use a MegaCycle 126-00 cam, but it will be 2-3x the expense.