Do your engine a favor, invest in a set of matching springs. 4speed + valve float (overrev) = dropped valve and (or) serious damage. It is not wise to invest in a cam without the proper springs.
"Stupidity is Ignorance on Steroids" "Yeah, it's hopped to over 160" (quote by Kowalski in the movie Vanishing Point 1970 - Cupid Productions)
