When I ordered my 3K GSK for my '98, it came with 4 springs. Turned out the 4th was for a 4K kit. Probably cheaper and easier for the supplier to stock just one kit instead of 2. At any rate, install all but the smallest spring for 3K. If you want to install 4K, put them all in. Make sure all the washers are removed as described in the intructions.
FYI only, I found that the Gov. lever was passing below the plate after install of the 3K GSK and I had to adjust it up to hit the lower edge of the plate. Ran great after that.
Dan