I'm looking at this to convert my 1970 convert to Sniper EFI 550-510 system. It says it fits a 1970 chevelle, monte carlo, el camino AND GM A BODY. So I would think they would fit. Just like to double check to see if anyone has used one before I order one up.

Thanks, John

 

Try and contact DC2X4DRVR Lance here. I believe he put a sniper system on his 71-455. I may be able to help you. Once upon a time he was not real happy with it.

 

i have the EFI on my olds 350 t works perfectly so far wet with a external fuel pump set up

 

I installed the Holley returnless pump, works good. After 2 tuning sessions with a pro Holley EFI expert my car runs great.

 

The Tanks Inc tank and internal fuel pump is one of the few things I have no complaints with the EFI conversion.

If I remember correctly, they have 2 different tank designs. One looks very similar to a factory tank, the other has the lower front corners trimmed for additional exhaust room.

Id strongly consider upgrading to the float less style sending unit. The float on the standard sending unit isn’t very accurate below 1/4. From what I have heard, the float isn’t heavy enough to fall on its own once the fuel level drops. Some people have “fixed” this with brazing a large nut or washer to the float arm.

It’s embarrassing to run out of gas!!

 

If you have not already purchased a Sniper, I highly suggest you skip the Sniper 1 and get the newer Sniper 2.

 

Also have this in my stock 70 Cutlass S, seems to work OK for the SEFI but I'm not making big power. I went for the bigger pump, just in case, for future considerations.

 

Sorry, work, life and slow upgrades I haven't moved forward with EFI yet.

Still note sure if I would go this route with the intake Holley pump for my Sniper? I do have an external 450l pump now, so do I need to spend the $$$ for this? BUT more importantly is I might be swapping out the tank and therefore the Holley system might not work with the different tank.

 

If your pump puts out enough psi and is properly positioned, it should work OK for EFI. I know one guy with a 71 Cutlass who had issues with an external pump and a Sniper EFI.

 

The Holley EFI requires 60psi.

 

I ordered a Walbro 450 pump. Basically un upgrade over the pump that comes in the Sniper kits.

 

Mine puts out 65 psi, 64 psi hammering the throttle around a corner with a 1/4 tank, according to my Innova fuel pressure gauge.

 

Resurrecting the thread looking for some help. My wife bought me the Sniper 550-511D kit a couple christmases ago but life and little kids caught up with me and I am just now getting around to installing. I ran into a snag

1. @dc2x4drvr and @matt69olds how did you get the returnless style fuel system to work with the tank? I measured the stock tank (just under 7 inches) and also bought the Tanks Inc EFI ready tank (https://www.summitracing.com/parts/TNK-TM34R-T) (6.25 inches), neither meet the minimum 7.25" depth required to install the returnless pump. Did you drop a some sort of spacer on the top to add the extra height?

Also, are either of you running electric fans controlled by the ECU? Another christmas gift from another year that has yet to make it onto the car is a cold case radiator with dual electric fan set up.

 

I put a Cold Case radiator in my 75 Hurst Olds and it dropped the temp about 20°.

 

The Holley pump I used fit the tank, they don't sit exactly vertical. I installed the electric fans in a stand alone configuration, relay for each fan, and the fan thermostat is in the radiator.
Good luck!

 

Thanks. Any idea what pump you used? I was looking for an install thread and didn’t see one from you. any chance you made one?

After messing with the original tank some more, it looks like I can shift the position of the pump over toward the drivers side just a touch which puts it on top of the ribs and get the height I need. Now I just need to go get the tank steamed so I don’t worry about sparks while drilling the hole.

 

Unfortunately the Sniper 1 only has a single fan trigger, you can use it to activate two fans via a relay and it will work just fine... but ideally you'd use another controller to have one fan turn on at ABC temp, and the other fan turn on at XYZ temp. However that adds wiring and may not be as easy to make look nice n tidy, if that's your thing.


https://ceautoelectricsupply.com/pro...ative-trigger/

Or if you prefer to do your own wire harness: https://www.leashelectronics.com/pro...p-relay-module

 

I used this Holley OE pump, fits perfect in stock Olds Abody tank.

510-12-373

 

that is really helpful thanks! Just so I am tracking, the rely kit you linked will turn both fans on together correct? The downside to both coming on together is more cycles? Kinda like having too big of an AC compressor for your house? Have you played with adding a second controller?

 

well that looks like it will work much, much better. And I now realize that the part number is in the title of the thread 🤦‍♂️ Thanks!

 

I've installed allot of Sniper 1 systems and they have two fan outputs. I have one in my 67 Chevelle and one in my 71 442. Although I use relays and only one of the outputs....two are configurable.

On the return less pump.....I've installed several of them before but dont like them on high HP cars that are driven aggressively like I drive mine. I dont like the delays in providing the WOT fuel requirements. A separate return line is hands down.....way better.

 

where did you mount your inline fuel filter? Spliced into the hard line on the passenger side frame rail?

 

My fuel filter is inline with the rubber fuel off the pump, connected to the hardline. BTW, the Holley pump fuel line is a little hard to connect, probably easier if the tank is left loose to allow more room, also check the dia. of the Holley line, IIRC it’s smaller than the Olds line.

 

Here’s a pic, used a GM fuel filter.

 

I mounted a 100 micron cleanable filter just after the pump with 8AN fittings and line. I replaced the one rubber section on the factory line with the braided 3/8" hose and dual efi clamps on both sides to the factory steel line. Then I have a cleanable 10 micron filter just before the Wilson injector rail. The 12-373 puts out a solid 63-64 psi according to the Holley sensor, within 1 psi of an actual mechanical gauge. The cheap $20 Amazon sensors read 10 to 15 psi low, don't buy them. I can see a returnless system not delivering as fast for high performance builds, rock solid on my weak build and dropped right in and the factory gauge works. For fan control, a dual 40 amp Davies Craig fan controller works fantastic. I do like the Sniper 2 comes with it's own fuse box setup. I should have bought an actual EFI adapter harness for my Terminator X Max, many electrical issues, just too much for 50+ year old wiring.

 

Awesome, thanks for the pic, that is really helpful. I bought the new 12-373 from Summit and fortunately they have an warehouse about an hour from me. Drove down there to get it, got it home, opened it up, and it was used. Plastic package was already open, filter sock was dirty and the connection at the bottom of the pump looked like it had already had fuel run through it. Should have checked it before I left. Live and learn. Called Summit and they are sending another one fortunately, but didn't have any more available locally. Hoping to tackle this as soon as the package comes in. Still need to run the wiring as well. As I was looking to run the battery leads, figured I might as well swap out the rotted battery tray. Man are those bolts a bear to remove when they are corroded. Ended up having to grind them down and now working on punching them out.

 

Thanks for the suggestion on the Davies controller, I will look into that. Been poking around and found the painless harness ( ) since I have AC as well though it needs to be rebuilt as well. Not sure if it is going to work or if I would be better off handling the fans now, and add another dedicated AC relay if / when I get the AC working.

 

https://www.summitracing.com/parts/dcw-dc-0445/reviewsHere is the controller I used. I used the push in probe, not really a fan of that style. The thread in probe worked very well.

 

finally back at this over the Christmas break after being out of town. I think I have a plan for all the connections, which brought up another question. How did you run your wiring? Did you go up through the trunk and try to follow the ribbon under the drivers side seats or did you run it along the fuel line under the car in a loom? Seems like through the trunk is the better option, but worried going under the carpet is going to suck. Probably over thinking it…

 

I ran mine thru the factory ribbon conduit.

 

Ran it in a loom with steel rubber clamps along side the fuel line on the frame, connected to a Mr.Gasket fuel pump relay.

 

Mine drops through the trunk over the rear pumpkin. There's less exposure to the elements inside the car (I actually drive mine).

 

My fuel pump relay is in the trunk, the wiring from the front is routed underneath the threshold plate to the relay, all covered in nylon braid.