I’m pretty sure the Mustang was built on the Pinto platform for a while.
Don’t know the answer to your question though.
The “Mustang 2” was a slightly restyled Pinto with the really crappy 2.3l 4 or the 2.8l v6 (the 302 came later and made about 130 hp) , many people within Ford wanted to do the 1974 mustang on the Maverick platform , very similar in dimensions to a 68ish Mustang, and a low cost car..