I'm reading over posts and looking over the tutorial (How to replace your mechanical fuel pump with a Facet Duralift electric fuel pump) but none of them seem to cover the source connection.

Do you connect to the supply line that was leading into the mechanical fuel pump or do you connect to the tank selector valve?

Pictures of how you did either would be great!

I've got everything else covered (relay, pump, etc.)!

 

Well I'm not an expert but what I did was just take some 5/16" rubber fuel hose, slip it over the end of the existing hard line right by the old pump, and route it up past the vacuum pump to a 5/16" barb screwed into the e-pump. Working great so far. A good mod to do, the truck starts with less cranking.

 

Same. rubber line to mechanical pump supply. I done the bigblock chevy blockoff plate on mine too

 

That's what I wanted to know!

 

Make sure you test fit the block off plate before bolting it on. I first bought one from O'reillys and it was too big. I didn't check before running it and the plate had caught on the machined lip above the hole and bent, causing it to leak.

Spectra brand is the one I went with next, and that one was small enough to fit perfectly.