Well, keep in mind the 72 340 was the low compression smog version, if you want performance id say yeah put another engine in it or work that one, or save the numbers matching block if it is for when you go to sell it. Like said there are no pics,ifit is a nice car and its 10 grand or under id say go for it. key thing is like said, rust, and if its all there. Interiors rent cheap. i looked at a 74 Duster in the summer of 2019, 318 Auto car, 5 grand they were asking. it had frame rail rot on the Lf near the shock tower and no interior to speak of, other than that it rand and drove sounded good. I offered the kid 3800 and he dint bite but it was just as well..till I fixed the rot and installed a an interior I would have been in way over budget. i am a stickler for interior but that's me. I cant drive a car with no carpet ,door panels and no headliner the women dont wanna get into a car like that. :)
