Heavy or lightweight flywheel?

I would use the lightest flywheel i could find.
I replaced a 35lb cast iron wheel with a 13lb aluminum wheel, many years ago, in a 57 chevy with a 360hp 350.
I LOVED it! (I did have a scattershield, and 4.11 gears)
The motor revved instantly, pulled harder in gear, and with enough gear, didnt miss the smoothing effect of the heavy flywheel at all.
Heavy flywheels are used in heavy cars and some racing cars for the inertial effect, to leave an intersection, or a starting line. After the car is moving, extra flywheel weight just makes the car accelerate slower, as it acts as if the car is heavier. Visualize trying to spin a bowling ball tied to a string, verses a golf ball and a string. Which is easier to spin? Heavy wheels are used in small displacement high revving drag cars with great traction, where the car would stumble without the inertia. Vw drag cars are typical. Without a heavy flywheel, they wheelie, then fall on their face.