another stock fuel tank question.
 

In the final stages of my build and currently working on the fuel system. I've got the factory fuel lines from an 03. and plan to run them to the fuel filer and past that plumb in a walbaro pump. As for the fuel return I noticed the stock tanks have a vent on the passenger side of the tank as well as one on the driver side by the fuel neck. Can I plumb my return straight into that vent with high pressure hose? attached is a picture of the vent I'm talking about.

Re: another stock fuel tank question.
 

Not all 67-72 tanks have those hose nipples in the top of the tank, The two 69s & a 70 Ive owned didnt have them, Its a emission thing, Not sure when GM started doing that.......Ive seen 71s with & without it. But, Yes you can use them for the return line.

I highly recommend drawing fuel from the BOTTOM of the tank when using a external fuel pump. The last conversion I did to a 67-72 truck....I had my radiator shop weld a 1/2" nipple in the bottom of the tank to feed the pump. 3/8" out of the pump.

Re: another stock fuel tank question.
 

now that you mention it that does make sense the one I've currently got my 5.3 in is a 67 and has these vents. However I have pulled tanks out of 69's and 72's that didnt have them... is the main reason you recomend welding a bung at the bottom of the tank due to making the pump work to hard to pull fuel? Is there a reason classic trucks didnt do so ( on this build http://www.classictrucks.com/tech/09...l/viewall.html) , and many people havent done so on their builds with stock tanks? has anybody runing this set up on here experienced any issues with their pumps?

Re: another stock fuel tank question.
 

from what I have read, they stock pickup is fine connected to a external pump.

Although, in high hp applications, I can see where there may be a fuel starvation
problem. Hopefully someone else chimes in with more info.

Re: another stock fuel tank question.
 

I ran a external pump using a stock tank on my brothers 5.3 swap and it has been a dd for about 2 years now with no issues. I plan on doing it on my 68