I guess it depends on if you mean 5.2 magnum or actually a 318 LA block you are planning on putting into a newer truck.

when they 5.2 mag was put in, it was switched to 360 type seals.
so the 5.9 and the 5.2 use the same pan.

If you mean an actual 318 LA block, then the seals for the pan would be different.