If you're in the market for a new American car steering knuckle, there are a few important things to consider before making your purchase. 

Here are some key factors to keep in mind:

1. 1.Compatibility: The first thing you need to determine is whether the steering knuckle you're considering is compatible with your vehicle. Be sure to check the make and model of your car to ensure that the part will fit properly.

2.Material: Steering knuckles are typically made of cast iron, aluminum, or steel. Each material has its own strengths and weaknesses, so consider which one will be best for your specific needs. Cast iron is heavy and durable, while aluminum is lightweight and offers better handling. Steel is the most common material and offers a good balance between strength and weight.

3.Brand and Quality: Look for reputable brands and high-quality products. A good brand will have a reputation for producing reliable and durable steering knuckles that will last for many years. Be sure to read reviews and check the manufacturer's warranty before making your purchase.

4.Cost: Steering knuckles can vary greatly in price depending on the material, brand, and quality. While it may be tempting to go for a cheaper option, investing in a higher quality steering knuckle will likely save you money in the long run by reducing the risk of future repairs or replacements.

5.Installation: If you're not experienced with car repairs, it's recommended that you have a professional mechanic install your new steering knuckle. This will ensure that the part is installed correctly and safely.

By considering these factors, you'll be well on your way to finding the best American car steering knuckle for your needs. Remember to do your research and take your time to make an informed decision.