I had a 79 Cobra Mustang in high school. It was the 302 V8. Same two tone exterior color with red interior. Mine had the sunroof. Seeing brings back memories
The waste gate on this factory set up has a spring loaded dual hose vacum actuator. If you block off the large port, it will take more pressure to close the waste gate. You will get FULL BOOST!!! I think factory was 5psi, you will definitely double that!. You can't run it too hard tho. You will need to get the carb to dump a lil more fuel because it will run a bit lean with this extra boost.
I had one of these and the stupid turbo wasn’t intercooled and the turbo went bad and that had to be replace first off and the cobra package is just stickers nothing more . There was other turbo mustangs and they just lack the stickers .