I’m wanting to do an engine swap on my 2003 3.8 v6 and I’m pretty clueless on what motors will fit. I’ve looked it up and haven’t been able to find anything. If there are any motors that aren’t from Ford that would still fit in the engine bay of my car that would be cool too, not really looking for just a Ford specific motor, just anything that is bigger than the v6 and will fit in the engine bay. Now a LS6 545 out of a 1970 Chevelle would be badass but I think all of us can hope for that lol

 

ANY engine can be made to fit ANY engine bay, given no constraints on suspension re-design, cutting, bending, re-forming it's surroundings. Given that the 4.6 OHC V-8 was the standard 8 cyl. back then, it's nearly as big (wide) as many others.

OHC engines are inherently wider than OHV engines. The 4-valve 4.6 is even wider; 4 valves require two camshafts per head.

One very important consideration you will need to address early-on is the oil pan. Shape, size, and sump location often dictate fit or no-fit issues. A good example is the small block Ford engine, 289/302/5.0L. For many years, most had a FRONT SUMP. The Fox Body came along requiring a DOUBLE-SUMP of sorts, larger in front, but a space between them for chassis support. Thus, you can't stick a stock Fox engine (V-8) in an early Mustang, for example, without changing the oil pan. There are other issues as well, such as the shorter "front-end" of '94-'95 5.0s.