ever since i rebuilt the motor earlier this year it sounds like a lifter tapping.i even went as far as replacing the lifters again a couple of months ago.and yes i soaked them in oil overnight.the valve springs i put in were single springs with a yellow stripe on them.the original springs were dual spring.my question is would the single springs be too weak?and i'll also add that it's not the exhaust manifold,i checked for that.thanks.