Secrets for?

Insure your tolerances are uniform and exact! (ring gap, cam dial in, clearances)

Insure that your spring installed height, open and closed pressures are within cam specs.

Valves/angles are important.

Have Cliff Ruggles rebuild your Q-jet.

Insure your carb, intake, cam, heads all compliment the gear ratio of rear, trans and weight of car. Mismatching components by throwing whatever on the drivetrain will cause more problems than is worth.

Have your old distributor recurved..or at that recurve your new one.

Buy both Pete McCarthys books, subscribe to Pontiac Enthusiast, HPP and whatever Pontiac related you can and read.

You will not go fast or far without trial and error, knowledge and $$$. I highly recommend you just build it your way for now, take the car to a dyno session and have the operator make the changes to the motor (thats what you are paying for) just make sure to take alot of secondary rods and hangers for the carb and a few different sets of plugs in different heat ranges. Also, try to have your primary idle circuit adjusted prior to dyno session.