My days of smelling fuel in the garage and constantly adjusting a Holley carb are over. I'm tired of chasing AFR and watching parameters change day to day.

I'm considering an EFI system, but I'm reluctant to tackle the fuel system overhaul because of the costs (new tank, pump, sender, supply/return lines, regulator) and hassle. I overhauled my low-pressure fuel system a year ago, and the idea of starting over would be frustrating. Does anyone have experience with the fuel sump/pump options on the market like the Edelbrock Universal EFI Sump system or the FiTech Force Fuel systems? Are there any viable inline electric pumps that are quiet and reliable? I read a thread about the Walbro GSL392 pump. That might be an option. Speedway has a kit with the pump and a filter with built-in regulator. Too easy to be reliable?

Thanks!

Speedway kit

1978 F100, Ford 302, single aft tank, Holley 4160

 

There are companies that make dentside tanks for EFI setups. Tom's Off Road is one of them. Well worth the cost if you ask me.

https://tomsoffroad.com/products/efi...UaArGvEALw_wcB

 

IMHO, neither system is "reliable" or efficient, nor will they perform any better than a carb. There is only one benefit you are getting- no choke. I will say that if you are dealing with constant altitude operational changes yes there is a benefit to EFI but, the TB units, if 5 years there is typically no tech support. Parts good luck- they are typically oem but, from what, good luck once part replacement support is gone from the aftermarket mfg.

You will also need to change the intake- why- the oem manifold was designed for carb fuel droplets (pushing heat into the chamber atomizing the droplets)- not the finer spray of the EFI TB....it will just not respond and feel like it is never exactly in tune.

Honestly, unless you are traveling between high altitudes constantly, there is no reason for what you are advising is occurring- and I lived at one point in Lake Arrowhead california (elevation 5,200 feet) and traveled to San Bernardino 4 times a weeks (elevation 1,000 feet) and would drive up to big bear periodically which is about 7,000 feet. Never had to readjust the carb as you are describing.
Now, direct port injection (aftermarket), yes, it is excellent.

 

JJ,

My experience with on my 77 F-150, 351M/400 Holley Sniper 2300 (2 Barrel) EFI Conversion:

(a) Installed new Aft Axle 19 Gallon Aluminum fuel tank, P/N BW4236-20, and In-Tank Fuel Pump P/N 11540 Aeromotive Stealth. Purchased both tank with pump already installed in tank from Boyd’s Welding out of Florida. Sourced female Swivel fitting with Fragola P/N 499006-BL and Russell EFI-6X5/16” Quick Disconnect Adapter, P/N 640930. Used MOTORCRAFT OEM Fuel Filter P/N FG-872 from a 1995 F-150 and a Ford OEM Roll-Over Fuel Shut Off Switch from a 2006 Ranger. Obtained both OEM Ford fuel line (stainless steel pre-bent), frame mounted fuel filter holder and Fuel Roll-Over Shut Off switch from my local junk yard.

(b) Installed 2300 Holley Sniper (2 injector), P/N 550-849.

(c) Installed Holley Sniper EFI Distributor (Hyper Spark) P/N 565-303, for Ford engines 351C/M – 460, including their Ignition Box and Coil.

(d) Installed new tires 31 X 10.5 R15C and practically a new dual exhaust system with an O2 Sensor Bung welded in, re-used existing Magnaflow 11236 mufflers and stainless steel exhaust tips.

(f) Other items sourced from my local parts store included:

- 3/8” nylon, return fuel line.

- 3/8” stainless steel braided fuel line from the frame mounted fuel filter forward to the Holley EFI.

- Fuel line insulation and abrasion protector covering.

- 30 AMP Relay to wire the in-tank fuel pump.

With the initial EFI install, I experiencing hard cold starts, need to increase cold enrichment setting on the hand held wizard and occasional stalling when coming to a stop or red light. Was told that I needed to control timing, i.e., installed the Holley Sniper EFI distributor. Since the install Friday, (08 April 2022), the truck doesn’t stall anymore as mentioned above and is now very enjoyable to drive. The last photo was taken prior to changing over to the Holley Sniper EFI self timing distributor which eliminated all previous cold start and stalling problems. Would I do it over, yes, without question. (FYI), last Friday, (01 May 2026) took it in for bi-annual California smog test and it passed with no issues. Note the truck sat since November 2025 and I check fluid levels before taking it for the smog test, it started right up and burns allot cleaner compared to when It was equipped with the Motorcraft 2150 carburetor. Would I do it again, yes without hesitation.

 

If I ever go the EFI route it will be with the Edelbrock PFI system. Expensive, but more versatile and has an EFI intent manifold.

 

I had a Sniper 1 on mine, but was chasing oil consumption and weak spark from a Pertronix unit. Also a sporadic dead system from an interlock connected to an oil pressure switch that would switch right at lugging in 1st when hot.

Ultimately I spent a lot, and am still running the in-tank pump. Probably next year I’ll try the Sniper2, as I am also not a fan of the fuel smell, and constantly chasing a compromise in AFR depending on air temp.
My AVS2 is a great carb, but the smoothness of the sniper and the throttle response was unbeatable.

Just expect to spend at least $2k.

 

How were you able to pass SMOG check without the OE carb in place? I'd think that a different intake, carb, EGR changes etc would be a fail of visual inspection.

 

Walbro has/had a solid repuration as a one of the most quite frame mounted pumps on the market. Use rubber isolators, for the hdwr and wrap the pump in a piece of rubber before you clamp it.

Than I found this..."The Walbro GSL392 is known for being quite loud, with a distinct, high-pitched whine or buzzing sound described as a "sewing machine" or "whinebro," which can often be heard over the engine and exhaust. It is frequently cited as one of the louder external fuel pumps available".

Walbro 255 versus the MSD.
Do not have to get a new tank unless you want to get and use a in tank pump. Running a return line, easy if you have a EVAP tank, use that top port. Do not have a EVAP tank, just route it to you fillneck and tap there.

Single or dual plan intake matters when adding a Sniper.

 

Thanks, Beechkid. I know - it doesn't make sense. But yesterday I started the truck that I tuned this weekend, and the AFR was now too rich and the idle RPM was too high (after choke was off). I warmed up the engine and retuned idle. In park, I was idling at 900 RPM and an AFR of 14.0. Went for another drive, and when I returned, the AFR in park was 15.5, and my idle was above 1,000. I'm not sure the AFR gauge has made my life any easier. All I see is the rich condition when I'm coasting or downhill, a part-throttle transition that I can't seem to get right despite different power valves, and a WOT that goes too rich. But today when I drive it, I could have entirely different observations. Over the weekend, the accelerator pump was the issue. The adjustment arm spring was sloppy even at it's loosest point. So I drained the fuel, tore the pump apart, put it all back together, and suddenly the spring arm is making contact with the pump arm. No explanation for what caused the issue. Maybe EFI isn't the answer, but this Holley 4160 doesn't seem to be the answer either.

 

Ha! That seems to be my experience tracking down reviews - 50% love a thing / 50% hate it. I have an evap tank, but I'm using the vent that runs to a carbon canister. I've seen people route the return to the fill neck, but I also read that you should return the fuel below the liquid level to prevent creating more vapors and introducing air bubbles. Maybe that isn't a real concern. I have an Edelbrock Performer 289 dual plane intake, so I think that would be a good fit for any of the TBI EFI systems. Thanks, Rich!

 

MaddogJohnson,
Purchased my 77 F150 4x4 in Casper, Wyoming, CARB referee performed smog inspection and test, it passed. GVWR of my 77 F150 is 6050 LBS DOS code of Denver making it 1977 Federal emission standards not California's. Because of the GVWR from the factory for Federal emission standards the truck was originally configured without an EGR valve, no air smog pump, no CAT and the fuel gauge does not indicate "Unleaded Fuel". The aftermarket intake is 50 state legal.

--- Break ---
JJ,
Couple of years ago my co-worker swapped engines in his late 60s Mustang to an OBS 5.0L and used the pictured in-line fuel pump, it's been working fine at least 6 consecutive years now and he uses the Mustang at least twice a week for work.

 

My experiences with aftermarket EFI systems have been mixed. Some good, some terrible and the overall cost of the system doesn't seem to have a lot to do with how well it all worked. One thing that always really bugged me about aftermarket systems is that it makes you reliant on aftermarket parts so if it conks out a long way from home it could be an issue. As an example about 15 years ago for a customer who built a Mopar every year for the Hot Rod Power Tour I built an engine using the Edelbrock Pro Flo 2 system. It was a 440 for a 63 Dodge wagon. The main goals were to try to get 20mpg and still run on the cheapest gas. Performance was really secondary. I built the engine and spent a lot of time running it on my dyno getting the fuel map from closed to wide open built at each RPM interval. At the time Edelbrock didn't have any premade calibrations for an engine as mild as this one. I got it done, cold start enrichment and everything worked out very well. Made 400 horsepower too.

Installed the engine in the car, did a little bit of fine tuning and it ran great on the Power Tour. It got 18.5mpg and never pinged on 87 octane. BUT later it started to run weird, leaned out. We checked fuel pressure etc and it just didn't run right. So on a hunch the owner swapped a few parts around with new ones including the distributor which cured the problem. After than he started carrying a spare just in case. All was well and he went through about 1 a year until one day Edelbrock didn't have any more of the distributors which were made by Mallory. He did find an aftermarket guy who would re build them. How long will that last? Who knows.

My whole point is that I have a lot more faith in GM or Ford than aftermarket. If someone offered a kit that used a computer from say a Chevy pickup with a Vortec 350 but with some special programming so that it could run anything I think that it would be a lot better.

 

Dave,
Your spot on, defintely agree with everything you stated.

 

I convert every truck to EFI when I do the CV swaps. Normally installing either a 4.6 or Coyote from a late model vehicle. I use the Tanks Inc tanks, their fuel pickups and Walbro pumps. I also run PTFE hoses and adapt it to fit the factory fuel rail with Russell Fittings. You cannot go wrong with this combo:




I also always run an inertia switch to kill the pump in case of an accident.

 

Thanks for sharing your experience and parts list, EQCMCAT. Great info!