440: Rebuild, Replace, or Sell

Hey all, I'd just like to pick your brains. My 440's oil pump had decided to stop sometime while driving the car to get the carbs rebuilt, which led to the engine stopping at a light. My question is, given the options of rebuilding the engine, replacing it with a crate engine or already rebuilt one, or selling the car (I got an ok deal on the price of the car and am not too deep financially into it), which would make the most sense logically/financially? Also, the older Mopar mechanic couldn't even turn the engine over by hand. Thanks!