225 Max Performance Recipe?

Hi All
I'm new here and working on my first project.
It's a 73 Swinger. Pulled the 225 and sent body to blaster.
I am trying to decide which way to go for power.
Either swap the 225 for a 340 or 360 build. Or maybe build out the 225 I already have.
Any insight on this? What HP can be realized from a 225 with mods? Any recipes for success?
I would also like to be able to drive this on the street.
Thanks
Dan