I dont think with a 429" you wuill have any loss of torque, nor make things easier by limiting wheel spin. That's all going to be up to your driving. Like Super says, heavier will always take away power. Iron heavier flywheels store more energy than aluminum. But, they also take more energy to turn. There's no way around it. So it all comes to your driving. If you've ever heard a Cup car leave the pits, they have very light multi-disc cluthes, so the rpms have to be raised to not stall when they begin moving. Iron can help with shift recovery on the drag strip, and they do in my opinion make street driving easier.
