The problem with an Edelbrock head, Speedmaster, ProMaxx, and any other Edelbrock copied style head is they start out around 170 cc intake runner. After around 195 cc you run out of GOOD area to take material from. Several of the heads that were pushed much past this point without moving the pushrod raped the shortside which was already a piss poor design. You are really walking a tightrope because to shape it right you have to lower an already low area.