Clay can have stacks of 200 items and clay_brick burtime is 2

minetestforfun_game/mods/default/crafting.lua

@@ -899,6 +899,7 @@ minetest.register_craft({
 
 minetest.register_craft({
 	type = "cooking",
+	cooktime = 2, -- //MFF(Mg|07/24/15)
 	output = "default:clay_brick",
 	recipe = "default:clay_lump",
 })

minetestforfun_game/mods/default/nodes.lua

@@ -420,6 +420,7 @@ minetest.register_node("default:clay", {
 			{items = {"default:clay_lump 8"}},
 		},
 	},
+	stack_max = 200, -- /MFF(Mg|07/24/25)
 	sounds = default.node_sound_dirt_defaults(),
 })