VT & Crower stage 2 cams

I thought valve spring upgrades were recommended for vt stage 2's. If there isn't a rep lurking on the site you could do a google search. I know another forum that sells them... but I don't think i can type it in here.
 
I'm using the crower stg 2 NA cams with patriot perf valve springs. Seems to take a little of the bottom end away but then at 4k the car opens up and will run strong to just over 6200. The "lopey" idle is kind of lame. You can hardly tell it has cams in it. I make 281hp/283trq on 87 octane. Before my underdrives, 373's and my tune I ran a 13.9 at 105. So if I can learn how to drive I should be mid 13's i would think