Since I don't really recall (but memory isn't perfect) any Cherubini 37' owners on the forum over the years mentioning the need to raise the boom, maybe just to suggest that you see if the boom is hanging down -- i.e. drooping.
If your mainsail is old (or even original) I have read that a design element way back when our boats were made was for mainsails with a long leach in relation to the luff. Something about achieving a more sail cloth area. The boom as a result would hang down at an angle lower than horizontal.
If so, then having the bottom of the sail re-cut for a shorter leach length might be an easier solution than raising the entire boom by removing and re-positioning the goose neck fittings on the mast.
When I bought my 1980 Cherubini Hunter 36 in 2007, it was still fitted with the OEM mainsail. The boom drooped. And with 6.3" me standing in the cockpit, was at my upper temple height. A replacement mainsail yielded a safer 6" clearance above my head. The leach of the mainsail can be shortened even more so that the boom actually has an angle above horizontal. May not need to be much to provide the clearance you might be looking for.
