budget street motor 360 or 383 for 71 duster

Well put. I was forming the exact thoughts into a reply when I saw this. Although I agree with RRR that the weight difference between a 360 and a 383 may only be about 150 pounds, that 150 pounds is right over the front wheels. And you certainly can lighten a 383 with aluminum parts, but you can do the same thing with a 360. You already have everything set up for a small block. I would go with a stroker motor. That is only my opinion, but that is what you wanted.

No, that's not what I said. The weight difference between a 440 and 360 is about 150 pounds. The 383 and 360 are even closer. Add aluminum intake and it's closer still.

To the OP, do what you want. But remember, you DID ask for opinions. I have run both 360 and 383 in a bodies. I liked the 383 more. You don't see big block Darts often because people don't have the sack to put them in. I like bein different. When you pop the hood at a car meet and have a big block, it's badass. Anybody can put a small block in one.