Been a long time since I messed with mine but my question would be, did the assembly come with isolators? If the new springs had isolators supplied with them and you already used them, then I wouldn't worry about it. But if not, then I would say that something should be up there. Their purpose is to absorb some of the vibration so as to not transfer it directly to the body. Just a thought.

 

Call Arnott and ask them...