My 273 turned out to be a 318...what did I buy?

The hose on the passenger side is the fuel line to the electronic pump mounted to the frame rail out of view. The red wire is the feed to that pump. Certainly an opportunity to clean up the wiring. I appreciate all of your insight and time. This is so helpful for someone with limited experience. I am an engineer by trade so I want to digest and understand all of this. I have the factory manual, Stockel's Auto Mechanics fundementals, and Peterson' Automotive Troubleshooting and Repair Manual that I have been diving into. But being able to ask real people about things is much more helpful. Thanks again!

Motors Manuals are nice references as well

https://www.ebay.com/itm/223766950211