Everyone knows how expensive a built motor/5.4 can be, and probably decided to go pushrod because they didn't have the funds. You can find a used pushrod cheap, especially a Chevy...Probably found a setup for 1k or less with tranny..
There was a time that I was going to go with a BB Ford Crate motor after I blew my motor the first time but decided not to...Sometimes I wish i would have went that route.
It's easy to spend 12-15K on a decently built motor with supporting mods. Obviously there are plenty of used L stock motors around but maybe the owner didn't have the funds to afford one when he needed one.
With the market driving the prices on these trucks down they are much easier to afford. It's easy to forsee some newbie blowing a motor and looking for an easy cheaper way out. Who knows. Different strokes for different folks.
On a side note it's nice to see something different other than the same ole cookie cutter setup that everyone else is doing....Although, I personally would never throw a chevy motor in a Ford truck.