the 318 oil pan won't work.
the 5.2 uses the 5.9/ 360 pan.

You have to use the gasket for the pan you are using.
That is, if you use the mag pan, use mag gaskets.
assuming you can use a truck pan.
I mean I know you are putting it in a truck, I just don't know about that truck. I only do cars.

If you use a 360 pan, because you need to shift the sump, then you use the la gaskets for a 360. The end seals are different.
If you use the mag gasket on the la pan, the gaskets have a gap.
The la gaskets are too thick to fit on the mag pan.