Here is my predicament. I have a 87 305 carb car, that I am putting a turbo'd 5.3 in. Now the stock fuel system doesn't have a in-tank pump. But I am looking at running twin walboros gss340's in the tank. Or, should I just run a big external pump.
Do I need to sump the tank?
If I run the twin in-tank pumps what do I mount them to? I don't think the sending unit hangs down in the tank, or does it?

 

The sending unit hangs down into the tank.

I'm not familiar with mounting dual in-tank pumps. Perhaps it has been done. Maybe the Power Adder types? I believe I've heard of it with the 4th gen LS1 tank, but couldn't provide any details.

It would seem sumping the tank would be the easiest solution.

 

you may want to double check the in-tank setup - my carbed 87 had the a helper pump in the tank. however, i opted to grab a newer tpi unit so i could use a normal FI pump and ran with the walbro 255.

the sending unit opening's pretty tight for a single pump as-is, probably best to run a sumped setup so you're not restricted by the stock provisions. or run with a 4th gen tank and go with some of their dual pump options

 

Thanks for the help guys but I think I found what I need as far as info. Check out this setup. I already have the pumps, now all I need is the lines. I will be ordering them tomorrow.
Check out the thread below.


https://www.thirdgen.org/forums/fabr...al-walbro.html

 

Your target power output will tell you if you need dual pumps or not. I run a single 255 in tank pump on my magnacharged LS1 at 7psi boost and the pump keeps up fine.

 

That eliminates the fuel gauge sender, if I'm seeing it correctly.