I am sumping a new stock tank for my car. It has 1/2" NPT female outlets.
If I run -08 line to the carb, should I use a -06 return line? Where on the tank should I dump the return? I was wondering if it would work to dump it in the 2nd sump outlet. Would it need to be on the top of the tank or would it make a difference if it were dumping in the sump. If I need to dump it in the top, should I order a 3/8" NPT fitting?

I am wondering if the pumping into the weight/pressure of the fuel would be a problem... I didn't know if the return line is just supposed to Niagra Falls its way into the tank from above.
I hope this doesn't top the list of dumb questions asked on this site.
I did a search and couldn't find any return line location posts.
Dylan

When I built my fuel system for the Nova, I used all Mallory components. Mallory clearly stated that the return line must be the same size as the feed line. If it's smaller, the fuel pressure will read incorrectly due to a pressure build up in the return line.
And the fule return must be in the top of the tank, above the fuel level.

Ron

When I built my fuel system for the Nova, I used all Mallory components. Mallory clearly stated that the return line must be the same size as the feed line. If it's smaller, the fuel pressure will read incorrectly due to a pressure build up in the return line.
And the fule return must be in the top of the tank, above the fuel level.

Ron

Ditto

Here's a good page to read about fuel systems -

http://www.centuryperformance.com/fuel.asp

Thanks!

I did my first aftermarket efi fuel system with the return smaller than the suply. It did not work, pressure wouldn't regulate properly.