Looking for advice. Want to build a Duster to run on a budget.

patience is definitely the key to building something on a budget. I bought my first 4bbl carb from a scratch and dent discount store in town. it was a marine qft 600cfm black anodized. it was half off. (after running the pos 2bbl for a while.)
Also, ingenuity is the other key to cheap building. I had a 60s mustang radiator in my car a friend gave me for free in my car before I pulled weeds in my backyard to earn a cheap ebay aluminum radiator my parents helped me buy.
I'm not saying that things haven't gone up in price, but there are still ways around it. Instead of trying to get a 70 duster or demon, get a 75 dart or scamp or something. while ugly, it will be cheaper then change the nose later.

Dodge dart 1974 $2000. 225 motor 6 cilindros

this is a b body but its still a mopar
1964 Dodge sedan

1960 Plymouth valiant

1965 Plymouth valiant · 4 door

1972 gold duster

1966 Plymouth Barracuda V8 I might acutally go look at this one :lol:

1970 Dodge Dart · SE Sedan 4D
This guy will trade for a 450cc dirtbike. interior is mint

1973 Plymouth Valiant
I considered that 72 duster for a good long while.