You'd need all new standing rigging
(wires) unless they have that much slack at the turnbuckles which is doubtful. Technically it will allow more heel but depending on your conditions you might not notice. There's a lot of downward force on the mast base so make sure wherever or however you raise it that it doesn't come crashing through the overhead.
Your boom will be higher but an inch or two is pretty irrelevant. My $0.02.
I looked at raising my mast a few feet (by using a taller mast) and the biggest thing I was going to get out of it was increased speed (and heeling).