I think it depends more on the cam choice, than the springs. An aggressive profile should be broken in without the inner springs..First, it takes a big load off the lifter base, easing an already problematic area..second, it takes very little time to replace them, and you dont need air tools. I make it a habit to never run the inners on a cam that needs double springs, excepting roller cams.
Also, you want to make darn sure the Edeelbrock springs can handle the cam profile..they say "fits up to .600 lift"...but lift is NOT what you use to figure if a spring will work for your package. It's one factor of several. The cams I've used that need 340# open pressures are too large for the Edelbrock supplied springs in most cases. Also, if its a street car of any type, you want to use a heavier spring if possible. Not becuase it's insurance..because valve springs do fatigue, like anything else. A spring worked at near it's rated limit of lift will fatigue and lose tension far earlier than a spring with a little more pressure, that operates at 1/2 it's rated max lift. So, a street car that runs all summer will need new springs in a couple of seasons..where the heavier unit might not need them at all thru the life of the engine. $.02
