Yep, needs work. And expensive work at that. At least the Bronco for $1000 might be able to be started.
I wonder if it really is a 351C. They weren't put in these trucks, but the 351M obviously was and some people don't know the difference, which is mainly a taller block on the M. But, there's another significant difference - the C has a small-block bell housing bolt pattern and the M has the big-block pattern.
So if you buy that truck and expect to be able to use the tranny out of it on your 300 or Windsor, check first.
Believe it or not, when I first bought my 1984 Flareside a coworker of mine asked me what engine was in it, and when I said it had a 302, he asked me if it was a Cleveland...lol. He hesitated a bit when he asked, clearly having no idea what he was talking about (but making some effort to sound like he was in the know). He is old enough that he was around when Clevelands were a thing, he just wasn't a car guy.
1994 F150 4x2 Flareside. 5.0 w/MAF, 4R70W, stock.
1984 F150 4X2 Flareside. Mild 302 w/ 5spd. Sold.
1980 F150 4X4 Flareside. 300i6 w/ 5spd. Sold in 2021.
1980 F100 4X2 Flareside. 351w/2bbl w/NP435. Sold in 1995