How to determine the front face of an intersectOperation?

Hello everyone.

Assume that i am intesecting a part with a intersect operation, How do i determine which way is front?

In my script, i take a block and intersect it with another block

How do i define that i want the interections front face to be the smaller cubes front face?

This is the script that intersects the parts:

local function GetIntersection(smallcube,bigcube)
	local newhit = hit:Clone()
	newhit.Transparency = 0
	newhit.Color = Color3.new(1,0,0)
	local Intersection = smallcube:IntersectAsync({bigcube})

	return Intersection
end

I have been having alot of problems defining what surfaces are what. Sometimes front is back, sometimes front is nothing and sometimes the decal is heavily distorted among other things