another rx8 question, radiator upgrade
 

So I'm working on my buddies car rx8 and the top radiator nipple broke. :( It's old and fragile. So now I owe him a radiator, and I'm going to give him the option of paying the difference for an upgrade.

BUT! I was wondering if anyone knows if there are any mods or problems with fitment? Sorry, I don't have time to join the rx8 forum, but I'm hoping someone here is familar with it