Man, we got some experts here. Too bad there aren't any options to ignore on this forum.
Mac Pro supports the 1333 MHz FSB (in fact, your FSB is running at 1333 MHz right now). The new chips should work just fine (Intel promised as much a year ago). Someone here ordered a pair of Penryns from Newegg. Hopefully they'll report back.
Unless he installed X5460's or E5450's he would not have the fastest Mac pro in the land, the extra cache helps but does not of itself make for record speeds. X5482 and X5472 do not enjoy support for their 1600 MHz FSB on current hardware ( 5000X chipset max FSB is 1333 MHz ).
It does make one wonder why the person hasn't reported back with his successful upgrade and boasting about having the fastest Mac Pro in the land. Just makes one wonder.............
True but the installation procedure is the same.That's not Penryn processors...