So I ended up getting a nice billet alum air cleaner riser with an “O” ring from Summit for $18.00. It’s a 2″ riser that fits the 5.125″ Edelbrock carb. The stock air cleaner bottom outlet fits inside the riser with the O ring against the air cleaner. With the shorter Edelbrock carb and the air cleaner outlet fitting down inside the riser it places the air cleaner at about the same height as the stock 4GC with the air cleaner mounted. It’s a little smaller outlet in the air cleaner than carb but Edelbrock didn’t think it would be an issue. You look directly at the primary and secondary carb inlets when the bottom is mounted up so it looks like good airflow should be achieved with a fully orig air cleaner. If there appears to be an issue I would go with Joe’s suggestion of modern 14″ base. Does anyone think air flow would be an issue with the stock bottom?