Why doesn't my script successfully generate a biome and connect them together?

For some reason, my script isn't really working the way I want it to. it positions my first block and then bam, the rest are sent to variations of the vectors (1,1,1). I've tried to generate it multiple times. Is there anything I can do different to make it work? ( also nothing in the output) Here is the script:

_G.GenerateBiomes = function()
	local storage = game.Workspace.Biomes
	local Marsh, Forest, Savannah = storage.Marsh, storage.Forest, storage.Savannah
	local Terrains = game.ReplicatedStorage.Terrains
	for x=1,50 do
		local part = Terrains.Grass_Terrain:Clone() -- Creates a Part and makes it a descendant of Workspace
		part.Parent = Forest
		part.Name = "Generated_Grass["..x.."]"
		part.Anchored = true -- Prevents the part from moving.
		if x ~= 1 then
			part.Position =((Vector3.new(math.random(70, 100), 1, math.random(1, 84)) - Vector3.new(Forest:FindFirstChild("Generated_Grass[".. x - 1 .."]"))).magnitude/Vector3.new(83.96, 1, 77.71))
		else
			part.Position = Vector3.new(-357.015, 1.3, -872.373)
		end	
	end
end