The stock will work ( .500 and less lift), but....... you know the story!! IF there is a lot of mileage on the springs, change them!! Or at least have them tested to insure they are good!! One of the mags did an article on valve spring..." 20 HP with valve springs...." (?) any way it wasnt 20 HP "From " the springs, it was 20 HP because of the springs!! the valve was Bouncing off the seat!! cool?? so IF you can upgrade... Do IT!! Cool??
Just me.............................
Thumper