Been done.
Big, heavy, needs a shoe horn. You are good at fabbing stuff up, right? Don't expect it to bolt right in. Bronco frames are narrow, narrower then full size trucks, makes exhaust very difficult.
Most of the 390 stories I hear about start with "I had this good running 390 in the corner of the shop and wanted to see if I could make it fit". I have seen a Titan 5.6 V8 engine in a 350Z. With time, tools and talent you can shoehorn just about anything into anything. Fiat 500 with a small block Chevy, seen in person. BMW Isitta with an Allison V12 aircraft engine, I have seen pictures of that. Right now I am looking at dropping a 5.0 mustang engine into an '84 Chevy truck. Why? It won't be a simple bolt in. But I know where there s a super clean truck with a blown engine and I have a complete 5.0 sitting in the corner of the garage with no plans for it.
Don't believe it can't be done. But there are better options for the displacment and power.