Engine health checking help for a sunday purchase
Looks like a 360 with some hot rod parts. Since it has stock rocker arms on it, the cam can't be too outrageous. If you get the tunnel ram with it, sell it to someone who needs it, because I suspect that motor doesn't. Put an RPM or RPM Airgap intake on it with a 650 Brawler carb. Those are some funky lookin headers, but looks like they are maybe Hookers. If they are Hooker 5115's, they are B & E body headers and won't fit your car, but they are really good headers for someone who can use them. Get both converters if you can. Get a new throttle cable and buy a Chrysler adapter for whatever carb you buy. Holley and Edelbrock both sell one that fits their carbs to make Mopar throttle cables work properly. Get all the kickdown linkage for the transmission if you can. Even though it came out of an E body, it may work in your Duster. No crossmember changes will be needed if you already have the conversion mounts on the way. You may want bigger torsion bars eventually, but not needed just to get it up and going. Let us know how it goes!