340 oil pan questions

What chassis? Stock K member? If so, Milodon made rear sump Super Stock pans years ago, the issue being that a rear sump wants to take up the same real estate that your steering linkage occupy. They made one with a "pass-through" tube for the steering linkage. They don't list them anymore, so your best bet is used- here's a pic I pulled off racingjunk.com:
35960378-857-Mopar-Milodon-Drag-Race-Super-Stock-Pan.jpg


If it has the rest of the pick up that pan is worth $$$$$. Best chassis HP pan made.