Wondering if I can swap a 2003 5.3 in place of a 2005 4.6? It looks like the intake & exhaust manifolds will have to be swapped. Are the electronics in the 2005 compatible with the 2003 engine?

 

Intakes won't swap - the 5.4 is a higher deck, so the intake ports are further apart. Other than that, I can't say. You might want to ask in the 5.4/4.6 engine forum, or the specific model you have - F150? Explorer? What?