Like everyone else here is saying, it will not work. There’s been several threads on this forum about it in the past. I remember starting one myself a couple years ago.
On my 340, the mainsail is huge and the boom is 16’ long. The jib actually measured out to 108%. The boat came with a Doyle UPS, pretty much a code 0 that is about 135%, which is a way to get more upwind headsail area. It sets outside the shrouds and is pretty flat. I can carry into 60 degrees apparent and closer in light winds with a twing. The helm balances nicely with it up.