75 Mk III - 560-00 Megacycle cam question

Hello all,
It's been a while since I've posted, but I still check in often (lurk).

QUESTION: are the stock valve springs good for use with a 560-000 Cam or should I bump up to something stiffer?
Motor is stock except for Mikuni and Boyer.

Thanks in advance.

Mark
this cam should use the 3" radius tappet and the spring kit # 901-N or equivalent.
this info here: www.megacyclecams.com/catalog/catalog.pdf
CNN