I've never seen a 2.8 in one but the Mustang II's and 1970's Capris had those. Also some Rangers and the earliest Aerostars. I don't recall it being a Fox engine option but I can verify it one way or the other after work.
I worked at a Ford dealer back then when they were new, the 2.8 V6 was
a engine option for the first half of the 79 model year then they switched
to the I-6 200cid 3.3 for the second half of the 79 model year.
The I-6 continued to be used in 80 & 81 maybe 82 as well.