You've got some engine reliability to spare, stroke it out and lower the bore, that will free up some octane, and save some weight. not sure how you can run carbs but only have a 25 response... Try setting your compression around 10.1-10.3:1 and your ignition in the high 50's.
As a comparison I'm running a EFI v6 that makes about the same power, more torque across a wider band, and it only weighs about 190lbs.
Edit obviously the v6 below is not the one I described above, I swapped out the single point injection for triples to improve response and gain 8 hp. I'm still not sure it's the best decision but it improved the laptime and really that's the only criteria.
Okay my entry is in, sacrificed top end power for drivability after learning from the winner's battle.