According to Cambridge's Advanced Grammar in Use, (Unit 11D) only will is correct in the following sentences, but not going to,
If you look carefully, you'll (not are going to) find writing scratched on the glass.
If you move to your left, you'll (not are going to) be able to see the church.
because in a situation like the above, you are describing a future event that follows another.
I would argue that in almost all conditional situations a future event may follow another, and therefore it is not a reason to distinguish will and going to.
So my question is: Can going to be used here or not?