New to forum so may not be searching correctly. Want to get a set of progressive fork springs but see terms like stock, heavy duty, spacers needed, no spacers needed. Anyone have tips on buying the correct ones? Have watched videos and read installs and confused why some one would trim a spacer or have the spring drop below the shock top. Know there is a spring compressor so having spring not protrude seems wrong to me. Tahnsk for any pointers so I get the right set the first time. Thanks, Mike. 2006 GL1800 audio.