Sorry but you're going to find here on the forum that most people like USA cars, but to answer your question, if you put a chevy motor in the Mazda you're going to break every drive train part in the car, they are not built for power unless you have lots of money for up grades plus it's probably a front wheel drive car. WHAT HAPPENED to the 1978 El Camino you first mentioned in your first post.
Zip.
The 1978 El Camino would be like mine that i built in 1988, still same paint, still like the day it rolled out of the paint booth. It's a 1979.
