Rig Tension for Islander 37

[Beyond]

Hi guys, I've been having trouble locating ideal rig tension information for my 1968 Islander 37. Any suggestions? The shrouds definitely seem loose to me and I'd like to increase the mast rake a bit, but I'm not sure how much rake it should have. The boat seems too tippy and the main sail seems to pillowy when I'm sailing, even in light wind. The main sail is not that old, so I thought tightening everything and pulling the mast back might help.