I found a gt 40 lower intake for sale for $125.00 that is suppost to be for a 5.8w.
part number RF-F87E-9K461-BA
Is this lower intake for a 5.8 or a 5.0 and if you don't know. What is length/width of a 5.8 lower intake be.

Second- does a 5.0 upper gt40 intake off a explore fit on this lower intake and if so what is needed to get it to work in this truck.

 

Looks like that is a 5.0 Explorer lower, the 5.8 version is 11" wide compared to about 9" for the 5.0 version.

P.S. If you were able to locate a 5.8 lower then yes an Explorer upper will bolt right on but you'll need an Explorer or Lightning throttle cable and the engine wiring will have to be altered to reach the modified sensor locations on the upper portion.. off to the side vs front and center. And of course you'll want a single intake tube setup and air filter.. something that can be sourced from a junkyard or aftermarket suppliers.