Congratulations on your acquisition. I like the look and practicality of a 9 foot bed. If that is the original engine, it has Babbitt rod bearings making it more expensive to rebuild. That being said l would prefer having an original engine. If you can replace it for less cost than a rebuild then I'd do it but I'd keep the original on a shelf. What is the number stamped on the ledge to the left of the distributor?