Shoot me an e-mail at kevin@hughesengines.com with the answers to as many of these questions as possible and I will help you pick one out.
Engine size (cubic inch displacement)
Weight of vehicle, with driver (if a driver is used)
What category does your use fit? 1 thu 8 See below.
Altitude where vehicle will be run.
Desired ET or MPH
Present camshaft (duration @ .050", Lobe separation angle, lift etc...)
Final gear ratio
Stall speed of torque converter
Tire height and width
Fuel type
Static or Mechanical compression ratio
Iron or aluminum heads
Measured Compression Ratio
Intake manifold
Header type and size
Carburetor size
Rocker arm type and ratio
Will power adders be used? (N.O.S., turbo, supercharger etc...)
Cylinder head air flow numbers