The return line allows cool fuel to be in the lines as far as the filter - supposedly reduces vapour lock. I'm not sure that it is the pressure that is higher but the volume is - on the 6s anyway. Ken Quoting tom jennings <tomj@xxxxxxx>: The supply and return lines plumb to the three-legged fuel filter. Also, the > later fuel pumps run much higher pressure than the 60's cars. The pump > pushes fuel into the fuel filter, and the third leg returns a portion of the > fuel to the tank; I dunno why they do this, but a major side effect is > "normal" low fuel pressure at the carburetor -- without the third leg > returning fuel to the tank, the pressure is high. _______________________________________________ AMC-list mailing list AMC-list@xxxxxxxxxxxx http://list.amc-list.com/listinfo.cgi/amc-list-amc-list.com