On my old combo I was running the stock springs and the tuner said they were starting to labor around 7500rpms. I know others have spun them as much as 8000 with no problems. Unless your goal is to run faster than mid-low 10's, I think you should be fine with the stock springs.
well i know i have to change the seals and this time while it is out i was thinking with going with the modmax stainless valves and their spring kit. my stock valves were cut by TEA so if they are not a weak point then i wont change them.
that brings up another question are you still running stock cams?
my plan is this time when the engine comes out to do everything to the heads that i couldnt afford last time, plus add the novi 2k. not sure on what kind of power to expect, i am making 500 now at 6250 with a novi 1k.(flatlines at this point) i would think the novi 2k just bolted on would add big power. i dont want to get caught with something in the heads being a weak point and cause major failure.