[Schurkey]

Originally Posted by Sirrotica

Article about what companies make filters with return lines and why they work, along with part numbers and pictures.

https://esgcapitalinc.com/fuel-filter-with-return-line/

1. Wix and Purolator are both owned by the same parent company--Mann + Hummel. Best guess is that the Wix and Purolator filters are identical...buy whichever is less expensive.

2. MOST GM cars with "vapor return" have the vapor outlet on the engine-driven fuel pump. Connects to the same sort of plumbing as these filters would connect to, only the location is different. Specifically, the filter--placed between pump and carb--would vent vapor AFTER the outlet check valve(s) in the fuel pump, while a vapor-return nipple on the pump vents vapor after the inlet check valve(s) but before the outlet check valve(s). I have no idea how the before/after check valve issue affects operation except that you can expect all fuel between the fuel filter vapor-vent, and the needle/seat area of the carb(s) to vanish down the vapor-return plumbing when the vehicle sits awhile--and it's going to take some cranking to push the fuel back up to fill that plumbing again. OTOH, venting vapor directly from the engine-driven fuel pump will make the pump more efficient.

3. I am VERY hesitant to put HOSE on the pressure side of a fuel pump. Installing these filters between pump and carb means you've got sections of hose on the inlet, and the two outlets of the filter. There are plenty of OEM applications that do this...but you'd better be inspecting that hose on a regular and frequent basis.