This is the exact reason Triplecrown and I are looking for mid-range power instead of top end drag porting. A screaming top end power band just results in tire spin and slide, no go. Give it some grunt so you can get around the corners without shifts and have linear power like a 4stroke instead of a rock spitting peaky powerband.
Smaller carb, fill in the intake, shallow hemi or toroidal head, widened exhaust port raised no more than 0.020", stock timing, 0.040" quench. If the cylinder is already ported for peak, try running it without a basegasket, just use Yamabond or Tri-bond sealer ont the joint, and you may have to shim your head (thin aluminum sheet) to get the quench right. Motor will be a torquer instead of a screamer. You will run a gear higher and faster.
There is no magic bullet, you have to find the balance to win. If you can buy your way to the winner's podium, you will always find someone else always has deeper pockets than yours. Tinker and learn. Why are the Raptors winning? More hp? More traction? Figure it out and start putting more eggs in that basket!