The 1/8" Hinge Points are for 1/2A to .20 size models. The 3/16" should work fine for a .40 size plane as long as the tail surfaces are at least 1/4" thick, preferably 5/16" thick. If the stock is to thin then use the 1/8" hinges and just double the ammount of hinges used.
Hope this helps!!
Anthony