Please help plumbing new under bed tank for TF truck

[Jemo]

I just got my conversion tank that mounts under the bed but have some questions. I thought it was frowned upon (or illegal) to run your fuel line from the bottom of the tank? This tank has two 3/8" NPT bungs - one for the fuel pump and one for a return line if using fuel injection. Second, since the fuel bungs are so low, a gravity fed fuel pump is almost out of the question because you can't get much lower. Any thoughts?

Which fuel pump are you using? Is there an aftermarket fuel sending unit that has a port that pulls fuel from the top? I only see that happening in tanks with internal pumps and late model vehicles.

Jeff

[OrrieG]

I plumbed mine from the lower one (not on the bottom) with 3/8" hard line up to the frame, down the frame to an element type fuel filter then to the stock fuel pump. Don't know if it works since I haven't fired the engine, but no reason it shouldn't once the line is filled and the siphon effect takes place. You can get aftermarket senders with a pickup too, I don't have the catalogs where I am. I don't think it is illegal, common sense would dictate hard line not rubber. I figure if something back enough has happened to break the hard line up 2 feet off the ground I have other problems to worry about. I made sure I had a couple of bends in the line for contraction and expansion and movement. All the holes in the frame and any rub points are grommeted or have rubber hose wrapped around and secured to the hard line.

http://67-72chevytrucks.com/vboard/s...&postcount=241

[Jemo]

Thanks, Orrie. I'm using an electric pump though. If I mount the pump on the crossmember or frame, it's going to be higher than 90% of the tank. I'm unsure what to do.

[Atomsplitter]

Your fuel pump should depend on the flow and pressure needs of the motor.
It was suggested and I installed a Walbrow 225 (225 lph or 60 gph) for my 1995 5.7L LT1. I had a friend weld a bracket at the bottom-front of the tank and mounted the external pump. I purchased GM fuel line fittings and installed them on the pump and used the OEM plastic (Nylon?) fuel lines from the 1995 Impala SS. the same line connected to the OEM filter and fuel rail connections. Make removal of the filter and servicing quick and easy!
They also sell the same pump but for intake use.

http://www.autoperformanceengineerin...l/fpspecs.html

[Jemo]

Thanks. I'm going to go with a carb on a LS motor this time so a mechanical pump wouldn't work. Probably need about 4 or 5 psi?

[tmoble]

6-7 better if a Holley carb.

[nebdrummer]

im using the walbro 255 external pump as well. good for an easy 450hp.

I picked up that, some 8AN hose, fittings, a good inline filter, and a bypass style regulator. This is needed with a higher PSI pump. my pump is also mounted higher than 90% of my tank as well, and i have not had a single issue yet. it holds 7 lbs like a rock.

[tmoble]

what regulator are you using to break the Walbro down to 6-7 lbs?

[mr48chev]

Ok, I'm missing something here and a bit curious. What tank are you using? outside of a Model A Ford with the gas tank in the cowl I have never heard of "gravity fed fuel pumps" you will have to enlighten me on this one.

[nebdrummer]

the simple holley bypass style. -8 in, -8 return. Quiet as can be.

[nebdrummer]

http://www.jegs.com/i/Holley/510/12-803BP/10002/-1

[wyomech]

I am running a summit fuel cell with fittings on the bottom and a walbro pump that is mounted in the frame rail which is about level with the top of the tank and works fine