Best dual plane intake for 400 low deck

Edelbrock Performer is what I would be looking for. Others have mentioned the DP4B, but I'll tell you to avoid it because they are old and they alloy they used back then is soft.

Most if not all have had carb stud thread issues and have either had or need helicoils installed. I recently had a DP4B that required all four stud holes welded up and re-tapped.

For you needs I would go the Performer route.

Tom