ahh I can help you.
Sorry I'm ten days late! I have a 1978 Lancer 28 sitting right down the street. I can measure the dimensions you need, as my boat just came out of layup and refit. I'll get back to you in the morning after I have a chance to measure them. If you haven't stepped the mast, be aware that this mast is like nothing I have ever put up before. It is (somehow) the hardest and scariest mast I've ever had to raise. We have a Beneteau 323 on a trailer too, and that mast went up easier than the Mk III 28.It takes at least three people; one on a crane, one on deck to balance and secure the toggles, and one in the cockpit. We attached the halyard for the main to the boom, cleated it, and used two sets of racheting mainsheet blocks (attached from the end of the boom to the rear toerail) along with the crane as a safety measure to pull it up.30 years, and both owners agree the mast and rigging is scary to lift, but tough as a tank when it is set properly. I've been caught in gusts that made every line on the boat howl, whistle and groan, and never met trouble.If this is your first sailboat, it is a good choice for the Gulf as it is forgiving. I've been off the coast of Texas in terrible storms that would make you leave pucker marks on the anti-skid and she's tanked right through under storm sails. You can overcanvass it to where the winches are in the water, and at no point she'll go out of control. Our beneteau with two rudders would loose helm when heeled over in high winds during races. First boat advice - I would suggest that you pick up a drogue chute, trysail, and storm jib. Check your USCG required gear, and take a short ASA course.Welcome to the money pit!Robert Foster"I just saved a bunch on my car insurance... By fleeing the scene!"