260/5 vs 260/6

[LowR3V'in]

As internet lore says the 260/6 is stronger.

You can tell by the fins it's a /6, the /5 has a waffle pattern.
http://www.briangt.com/gallery/album...5464.sized.jpg

[Danny]

One bolts up to the m30, the other doesn't, I think. Different bellhousings?

[MR 325]

Maybe I am missing something but what the hell is the difference? Is one better than the other?

Thanks. :)