Regardless of the pump you choose I would run a return line from the reg back to the tank. You are deadheading the pump, which means is it pushing hard on the fuel while you are restricting it at the regulator. This puts a lot of strain on the pump and will kill it prematurely. The return line relieves that strain so the fuel you need goes to the engine and the rest goes back to the tank.
Pump should also be mounted as close to the tank as possible and gravity fed, electric pumps like to push fuel not pull it.

 

The inexpensive fuel pumps are obviously made with inexpensive parts, motor, plastic impeller, bushings instead of bearings. The really high priced ones, couple hundred-up, are for HD high volume, high pressure racing applications. The sweet spot for street applications is ~ 100.00. When you dead head them it's like you blowing hard into a pinched off straw, you're going to tire fairly quickly. You can buy adjustable regulators with a bypass bleed return line (Holly makes one), or Chrysler used a non adjustable pressure bleed valve on some jeeps and trucks (carbed 360 V-8 is one application), it resembles an oversized metal inline fuel filter with 2 outlets, one to the carb and one return line to the tank. Gary has one on his Jeep engine.

 

IMO there is no need to spend a ton of money on an expensive pump for a low pressure system. Even my walbro 255 in truck #2, which is a HP pump and will support my 400+HP engine was only around $75.
A carter pump installed correctly should last for years. Shop around, prices are all over the place for pumps.

 

I never go with cheap fuel pumps as I learned the hard way about 20 years ago being stuck on a two lane highway in the dead of a Kansas winter when it was 12 above zero out. Fortunately I was two miles from the nearest town that had a NAPA store so I was back on the road the next day with a better fuel pump.

 

I have a Holley regulator with three connections on it. I used one from the tank, one to the carb and the last one for the gauge. I can remove the gauge and run one back to the tank. The tank has only one available bung at the bottom next to the feed.

3 Questions:

1. Since it will be pressurized, can I run the return to the bottom of the tank or does it have to be run back to the top?

2. I have 3/8" fuel line going to the carb does the return require 3/8" or 5/16".

3. Can anyone recommend a fuel pump?

 

3/8" fuel line is plenty, no need to downsize on the feed, but the return can be 5/16".
Return at the bottom should work fine.
I will have to research pumps, but any low pressure pump should work fine.

 

be sure to check that the third outlet is a pressure bleed return otherwise the fuel will follow the path of least resistance going back to the tank rather than to the engine. Some Holly regulators are set up with a return/bleed port. If it isn't, you could plumb in a needle valve pressure adjuster in the return line. Can put a simple T in the line near the carb for your pressure gauge. You want to measure the pressure as close to the carb as possible.

 

The regulator I have is a Holley 12-804 with no return. Can you tell me more about the needle valve pressure adjuster?

Also, Carter tells me to use the P74019 universal pump. Should I be looking for something better than that?

 

That carter pump should work fine, but I have not used one. Guys above seem to have good luck with Airtex, so maybe consider one of them? With you setting up the fuel system correctly there should be no more outside issues to cause the pump to fail.
I think Ax is talking about a schrader valve, which is like a valve core fitting to put air in a tire. Fuel injected cars have one on the rail, it is a place to either bleed off the fuel pressure or a place to hook up a fuel pressure guage.
I would just get a regulator with a return port and either two outlets ports (one for the gauge) or one outlet and tee in a pressure guage so you can set the regulator.

 

Dave, you mean the bleed port? No, not a schrader valve. I've seen regulators with a spring relief valve that opens the return port at the high end of the range of pressure, somewhat similar in function to but much smaller than a turbo blow off valve. I've also seen needle valve type valves that restricted the return port enough to make the main line to the carb the less restricted route when the float is open. I'm not sure just what tecnique or technology is used in the Chrysler relief valve but it is simple in appearance. I don't know how much they cost I'll ask Gary Sat if he knows the cost and/or the part #.

 

A coomonly seen needle valve adjuster is often used in modified brake setups where it is placed in either the front or rear brake circuit to adjust the brake pressure. They were also used on old gas heaters and lights to adjust the gas flow to the appliance. In your case you would T the line after the regulator and install it on the return leg. There it would be used to add a small amount of flow restiction to the return flow so the preferred (easiest) flow would be to the carb until the carb float shut it off causing the pressure to increase in that line higher than in the return line. A needle valve is used rather than a gate or ball valve (on off) because the flow can be finely adjusted. I'd hold off tho if you can until I talk to Gary about that return line bleed canister on his Chrysler jeep engine with his electric fuel pump this weekend. If it turns out to be reasonably inexpensive which I suspect it will, that would easily solve your problems.

 

Ok, talked with Gary. Here's something to consider, especially for the price: Crown Automotive - Fuel Filter Kit - Fits 1980 to 1986 CJ:With 2.5L engine - 4WheelParts.com It's a combo fuel filter and return bleed valve used originally on AMC Chrysler engines and is only 5.00! It installs like an inline filter, the single port end to the pump/regulator, the larger double port end to the carb, and the smaller port goes to a return line back to the tank. This allows the excess fuel pressure/flow to return to the tank when not needed by the carb, so there is a constant flow of fuel thru the pump. That keeps the pump cool and doesn't have it pumping against a shut off line most of the time. Overheated pumps can also cause the fuel to boil in the line resulting in vapor lock.

 

that looks like a good cheap way to get a return line in place, then adjust your current regulator for needed pressure.
A similar corvette filter is very popular with the LS swap guys.

 

That seems like a great solution thanks!

I currently have a filter before the pump and another after the regulator. The filter and pump are mounted to the frame rail just under the top of the tank and about 5 inches higher than the tank outlet.

While I am re-doing it all, should I move the pump and filter lower to be even with the bottom of the tank where the outlet is or is it OK at the top of the tank?

Also, can I install the Crown Automotive - Fuel Filter Kit - Fits 1980 to 1986 CJ:With 2.5L engine - 4WheelParts.com after the pump or does it have to be after the regulator?

 

You want to gravity feed the pump, so the lower the better. Also normally the filter is only installed after the pump, not before, as it can cause a restriction. If you dont have a sock filter at the tank feed you can run a filter before the pump, but it should not be for very fine particles, just a trash filter. Myself I would lose it as long as your tank and lines are in good condition. Check with the pump MFG and see what they recommend.