Easy way of telling is simply stick a temp probe in like a AIT gauge and see if it makes any difference.

Something to consider though, by exactly how many degrees do those fucking queer things actually keep cool by and secondly the engine itself probably won't be kept cooler but the outer casing and head may lose be kept cooler by a few degrees. In the grand scheme of things is that going to make any difference. IMHO if you need better cooling get a bigger rad, decent hoses, decent cooling fans, decent coolant fluid and if you must quick opening stat and wire fan to cut in earlier.