Rero fit roller cam & lifters into early block?

http://www.hughesengines.com/Index/...earch=5321&searchmode=partnumber&partid=26114

Just wondering if anyone out there is running this type of setup or if anyone has opinions on them. I would like to fit them to an early seventies 318 for the following reasons: I like the idea of no cam break in, no worries about the zinc level in oils, the faster ramp rates compared to non-rollers and higher power potential. Jump in good or bad, maybe they wont make extra power in mild builds etc... let me know whether you think its worth the extra cost!