You should check the dust seals as well , no good replacing the oil seals if the dust seals are buggered, for that model I would get a gold valve for the forks , than you change the valving to suit your needs , you get the instruction and the specs .You can buy the tools of race tech , it will save you money in the long run , I use skf seals as well as race tech stuff , than oem next, keep a eye on the bushes like alward 25 said plus make sure you clean the internals good as these forks build sludge down near the valving area , which will make them work worse, remember that one brand of 5 wt oil is different to another brand of 5 wt , we use motul 5 wt in these forks with good results , I don't think you will feel much difference using a lighter oil, your better of getting the better piston and valving , than you will feel a difference.