The inline fuel filters I've seen on the vendor sites have female pipe threads on both inlet and outlet. To adapt one to a carb with female pipe threads, you'd just need an mpt x mpt nipple.
LINKDouble check the thread size and type. There's no such thing as 5/16 taper pipe threads. Are you looking at the adapter screwed into the Rochester carb? If so, remove that and you'll find the threads in the carb are 1/8 female pipe thread. You can use that on the inlet of the filter and connect your fuel line to it, which as 78buckshot says is an inverted flare.
