Biggest Cam?
I get my Valve springs(once a year when racing) from Jegs. I have been testing them. I have two seasons and 10K on this set. Shifting at 6,800-7,000...ALOT. when I freashened the heads and added the titainium retainers they were fine.
They list them at 155# closed and 450 open. I want to say we set mine up at 140 closed
I forget what open was. they run fine on Hydrolic(sp) rollers.And YES they are double spring
$89.95 a set 
Mike




