He's using the filter for the flex fuel S10 2.2L.The pictures you show of the fuel filter is the filter used in 1999 - 2004 Corvettes with a built in pressure regulator set at 58 PSI. Often times people use the Corvette filter when doing LS Swaps. The filter for a 2000 Blazer doesn't have a pressure regulator. Click on below:
2000 CHEVROLET BLAZER 4.3L V6 Fuel Filter | RockAutoRockAuto ships auto parts and body parts from over 300 manufacturers to customers' doors worldwide, all at warehouse prices. Easy to use parts catalog.www.rockauto.com
Are you trying to adapt the Corvette filter?
With those filter/regulators (or the corvette one which is similar), I usually use an adapter that is the female disconnect on one side and AN flare on the other side. If you have an AN flaring tool, you can flare aluminum hard line to match the AN flare, or you can get a second AN flare to compression adapter to attach to the AN flare.
The adatpers are available at https://www.amazon.com/dp/B07NN3CLSD and from most online "speed shops" (Summit, Jegs, Speedway, etc). You need one 5/16 to -6AN and a 3/8 to either -6AN (for 3/8" tubing) or -8AN (for 1/2" tubing). If you want to run flex hose (rated for the appropriate pressure), hose barbs are https://www.amazon.com/dp/B07K59CT1G/ (3/8 hose) and https://www.amazon.com//dp/B07DXVN9XP/ (5/16 hose).
If you want compression fittings on 3/8 hard line, use https://www.amazon.com//dp/B07BRKBZZM to go from -6AN to a 3/8 tube compression fitting.