1970 duster clone. need opinions.

In this case, I'd rather own the 5 litre.
NICE lookin Stang ya got there.
If you plan to trade for this car, and then "go through" it to make it look better, you might be better off buying a car that is in WORSE shape. Let me explain. For example, if you pay more for a car with fresh paint, but you need to fix rust, then repaint, why not buy a car that needs paint for a lot less? If you plan to have the bumpers chromed, why not buy a car that has shitty bumpers already, and simply buy the rechromed ones and ship yours off as cores?
You'll be miles ahead if this car is a 340, has an 8-3/4 rear WITH SureGrip, and doesn't need ANY engine work, but keep in mind that once you start digging in, you'll likely not want to bolt old, crappy looking parts back onto your car, and you end up upside down in the car QUICKLY. All the while, someone ended up with a CHERRY Mustang to drive.

If you really want a project, buy on old Duster, and make it what you want.

Pasta