I understand that and trust me I’ll be reading along but a 170 cc chamber will only flow so much so why not port the head then try to find the extra 10-15 cfm I guess you are hoping to find. Look closely at the chamber around both the Speedmaster and Edelbrock head and you will see why the speedmaster flows more. Valve shrouding. A man way smarter than I will ever be preached 15 max on the valve angles and hopefully under that number. That number seems to really come into play up top. Ex: 90-70-60-45-30-15