Anything you can smooth out in the heads and intake will help flow and will build upper rpm HP which I'm not sure is something you'd tap into that much if your only reving to 7 grand, also I agree with what the other reply stated you dont want a super smooth intake port, you want it some what rough to help keep the air / fuel mixture atomized before going into the clyinder rather than having it bead up in the port.
Now, as far as making the car any more consistent?
I don't think you will notice any change there.
The biggest thing I've found that makes a car consistent in bracket racing is by doing the SAMETHING EVERYTIME!
I.E. Same burnout, staging in "EXACTLY" the same spot everytime ( very important ), stalling up the motor exactly the same rpm each time,having the engine at exactly the same tempature each round( harder to do late in the rounds ) keeping up with the air pressure on the rear slicks and not changing it in eliminations much if any from what you dialed your car in time trials, a properly tuned engine and properly jetted carb are also important factors.
( CARB TUNING NOTE )
I like to go on the lean side a bit on my carb (we race nights) so the car doest pick up much when it cools down at night. A rich mixture will drive you crazy trying to dial in right cause the car keeps picking up numbers every round as the cooler more dense air makes more power.
Sorry for the book just trying to help.
Goodluck,
><Charles