73 340 SB Rebuild, Need Help Selecting Parts

I believe it's the same short block you can buy from Pace Performance who is a vendor here. You get a discount for being a site member also I believe which make it cheaper then Summit. Here's a link to their forum here. Pace Performance One to his superstore thread, Pace Performance Mopar Section link and one to his store crate engine page. Super Stores - Mopar SB/BB Superstore - Mopar Crate Engines

Hopefully that helps.