Q: plymouth duster 70' engine swap

While we at Your Mechanic do not perform engine replacement or swaps, I can tell you some basics. Considering you are looking to install a 2004 Ford engine in a 1970 Chrysler product, there will be an extensive amount of work involved in performing this engine swap. The 2004 engine is controlled extensively by electronics - computers, sensors, etc. Also, being a fuel injected engine, the fuel system requirements for it to run in the Duster will have to be accommodated as well. To run properly, all of that will have to be swapped over and installed in the Duster. Also, the Ford V8 is a bit heavier than the 6 cylinder you are looking to replace. The suspension may have to be modified to support that extra weight as well. The Duster’s transmission will probably not be able to A - handle the power of the GT engine and B - not even match up properly to connect to the GT engine. As the "car guy" saying goes, anything can be done if you are willing to spend the money.

A simpler engine swap would be to find a Chrysler engine that would fit into the Duster with less modifications. The Duster (in the U.S. at least) was available with the 5.2 ltr (318 cubic inch) as well as the 340 cubic inch engine. One of those would probably fit with far less modifications to the vehicle. Do some online searching as I’m sure there are companies that can provide you with all the necessary information and parts to swap one of those engines into the Duster at far less cost than having to modify so many parts of the car to fit the Ford engine.