I would imagine your valve float is minimal with the stock cam, but with the E303 you will start to see it, and depreciate your springs in the process.
I would imagine your valve float is minimal with the stock cam, but with the E303 you will start to see it, and depreciate your springs in the process.
Change the springs...you WILL have valve float if you dont, plus there not that expensive, but you can keep your stock rockers, their 1.6 ratio just not a roller which doesen't mean much unless your turning some high RPM's.
The stock springs are barely able to contain the OEM setup
These days ... all OEM parts are designed that way
Having said that .............
You got two things to consider IMHO
1) The older your OEM springs ... the weaker they have become
2) The new cam is gonna work those OEM springs harder
and
If they don't do the job of containing the VT now ........
Its most likely gonna happen pretty quickly if you don't upgrade
I'd change em out
besides
Its easier to do heads off rather than heads on