Edelbrock heads with OEM manifolds

Your not specific about which Edelbrock heads that you're referring to but I found this.

• Edelbrock offers two types of aluminum cylinder heads for small block Mopars: Performer RPM and Victor. The Performer RPM heads are designed for street and strip performance, while the Victor heads are more suited for racing applications. Both types of heads have improved airflow, combustion chamber design, and valve sizes compared to the stock iron heads12.
• The Performer RPM heads are compatible with the factory exhaust manifold bolt pattern, so you can use them with your stock exhaust system without any modifications. However, the Victor heads have raised exhaust ports and require headers with a W-2 style flange2. You will also need to modify your spark plug wires and possibly your headers to accommodate the relocated spark plugs2.