Is it really the sail.
I could very well be wrong, but I'm not convinced the problem is the size of your headsail. How do you do when it is breezy?The reason I say this is that the 376 carries its extra sail area in the mainsail. You've got the equivalent sail area of similar sized boats flying a 150% already. It could be that these boats are simply faster, or sailed better. If you are racing PHRF you should get a rating advantage for having the smaller headsail.In any case if you aren't doing significantly better when it is windy I really doubt the problem is sail area. If you are competitive in the breeze, then you might be right, but I can't imagine how you can improve the situation much. Maximizing the foretriangle area is the best I can suggest. Get a jib that is cut as low to the deck as your track & roller furling drum will allow. Push the leech of the jib back until it is just short of the shrouds. Bring the clew of jib aft even further, through the shrouds. A hollow leech will allow you do this even more. I'd be surprised if your current jib goes aft as far as it can.Also, for a real performance boost get a fully battened Kevlar main. I saw one on a 376 and it was the coolest looking Hunter I've ever seen. Suddenly the boat went from cruiser to very cool racer.