The Stovebolt Site Forums The Shop Area Engine Shop Fuel filter - 3/8 inverted flare

One way, although a tiny bit unwieldy, is to use a pair of these

https://www.tanksinc.com/index.cfm/page/ptype=product/product_id=619/mode=prod/prd619.htm

and a pair of 6an couplers

https://www.summitracing.com/parts/sum-220041

and a modern screen style take apart and cleanable fuel filter, like below, although there are dozens of other versions from other manufactures, all with different micron filters.

https://www.summitracing.com/parts/pfs-10217