hi,trying to raise the action slightly on my 330 , but the springs on the treble side are now fully coil bound. Do people just cut them slightly shorter ??

I'd take a look at the flatness of the neck first. However, there weren't any spring for years, so you can always take them out.

don't you need the spring to provide some compression for the screw threads , or is the string pressure on the bridge more than achieving this?? i.e to stop them backing off and coming loose??