If you are drag racing:
find a track/car
determine how quick you want to go,with the car you have determine how much power you need IE, a 3300 pound nova will run into the 12s with a 425 hp engine and 4.11 gears/3 speed auto and a fat guy driving.
every hundred pounds will save/cost a tenth or more. If its really a race car then use racing gear ratios.
The heads will tell you how much power you could make,the cam will tell you what RPM that it happens and or if you will meet t he potential of the heads. the CR needs to be factored in. The cubic inches will also determine when the power occurs
and all the stuff you learned last thread