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 occupies. 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:
View attachment 1715633313


I couldn’t find that on RJ