Zerotohundred

guys, any1 here have the experience in upgrading their wira suspension?
i mean from 1.3 to 1.6 suspension... as i know, the 1.6 absober n spring is bigger in diameter. so is the top mount different? i mean the black cover to coordinat the spring n to screw at the top. i ask a few forman n some suspension sellers, some said need to change. but some of them nvr mention abt that thing at all, say just buy the 1.6 spring n absober will do.
any1 could help me?