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Couple of suggestions for those contemplating a Sniper install:

8K views 25 replies 8 participants last post by  The mechanic 
#1 ·
Hey Folks,

I installed a Sniper Stealth on my ‘68 a little over a week ago. After a long bit of contemplation I figured the Stealth setup was worth the extra $100.00 to me just to keep the carburetor look. And I decided to buy their kit which included the external fuel pump and regulator Rather than going with a new tank and in-tank pump.

If any of you do this, spend the $35.00 on the Aeromotive fuel pump isolation mounts. I ran mine for a week with just the rubber-coated straps that Holley supplies to mount the pump with. While this pump is not obnoxious like the regular Holley red and blue units, you can hear it. Priming is very loud. I couldn’t hear it while driving, but could hear it when at a stop. Today I added the isolation mounts and I’d say it cut the sound down to about 25% of what it was without the isolators. You can now barely hear the pump when it primes and can’t hear it at all with the engine running. Just be ready to drill the straps to accommodate the 1/4” studs on the isolation mounts. The original holes accept a #10 screw.

Also, just buy the Holley throttle lever extender when you buy the system. It’s about $23.00, which is about $20.00 more than what it’s worth when you see that it’s just a straight, flat piece of steel with a dogleg and a couple of holes drilled in it. But moving the throttle actuation that little bit farther from the throttle shaft makes a huge difference in feel at your right foot. Without it, my throttle was very abrupt. It would all but stick closed until you gave it just enough pedal pressure to spring it open for a nice little burnout. Without the additional lever I tried running mine with no return spring, and with one, then two return springs. Nothing would smooth it out. Now it’s as smooth as glass and adding return springs just increases pedal pressure slightly without causing any bind or hesitation.

The aftermarket “Chevelle drop-base” air cleaner I was running on my Street Avengers fits the Stealth throttle body just the same. That is, I have to run a 1/2” spacer between the throttle body and the base of the air cleaner just like I did on the carburetors. Also, with the throttle extension installed the throttle crank still clears the air cleaner base. Essentially, the clearances on the Stealth throttle body mimic that of a standard Holley carburetor.

If you have a nice braided inlet hose setup for a dual-feed Holley, it may or may not just screw right onto your new throttle body. My inlets on the Stealth are spaced about 1/2” farther apart than they are on the Street Avengers. ALSO, most Holley inlet extensions use a female AN fitting. The Sniper uses a male inlet fitting. And on that subject, the inlet fittings that Holley installs are too short. When you tighten up the supplied fuel feed lines the fuel hose is pulled very tightly against the throttle position sensor plug. Horrible design. I used a pair of -6AN male to -6AN female adapters which were plenty long enough to give the fuel inlet hose enough clearance.

AND... on the subject of fuel hose, you’ll need about 10‘ to 15’ more than what Holley gives you in their kit unless your car is an SS and you can use the factory 3/8” hard line. Mine is, but even still I used every inch of the 25’ that they supply. If your car has 5/16” fuel lines plan on spending money on more feed/return hose or hard lines.

Regarding the plumbing, for some reason Holley supplies one-too-few barbed hose fittings. I needed one more -6AN female to 3/8” hose barb fittings than Holley includes. As it turned out, I added a 2” pigtail to the tank end of my return line so that I could disconnect the return if I had to drop the tank in the future. Otherwise I’d have to fight with the fitting while trying to balance the tank in place. So instead of being short just one fitting, I ended up using two additional hose ends and one each of -6 male and female fittings. Also, had I not done that I would have come up 2‘ short on fuel hose.

That’s all I can think of for now. I’m very happy with the system. I just wish I had been prepared to buy these few little add-on‘s when I first got the system. It would have saved me some time. Hopefully this long winded post saves someone else a bit of time when planning out their system.
 
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#3 ·
Hey Folks,

I installed a Sniper Stealth on my ‘68 a little over a week ago. After a long bit of contemplation I figured the Stealth setup was worth the extra $100.00 to me just to keep the carburetor look. And I decided to buy their kit which included the external fuel pump and regulator Rather than going with a new tank and in-tank pump.

If any of you do this, spend the $35.00 on the Aeromotive fuel pump isolation mounts. I ran mine for a week with just the rubber-coated straps that Holley supplies to mount the pump with. While this pump is not obnoxious like the regular Holley red and blue units, you can hear it. Priming is very loud. I couldn’t hear it while driving, but could hear it when at a stop. Today I added the isolation mounts and I’d say it cut the sound down to about 25% of what it was without the isolators. You can now barely hear the pump when it primes and can’t hear it at all with the engine running. Just be ready to drill the straps to accommodate the 1/4” studs on the isolation mounts. The original holes accept a #10 screw.

Also, just buy the Holley throttle lever extender when you buy the system. It’s about $23.00, which is about $20.00 more than what it’s worth when you see that it’s just a straight, flat piece of steel with a dogleg and a couple of holes drilled in it. But moving the throttle actuation that little bit farther from the throttle shaft makes a huge difference in feel at your right foot. Without it, my throttle was very abrupt. It would all but stick closed until you gave it just enough pedal pressure to spring it open for a nice little burnout. Without the additional lever I tried running mine with no return spring, and with one, then two return springs. Nothing would smooth it out. Now it’s as smooth as glass and adding return springs just increases pedal pressure slightly without causing any bind or hesitation.

The aftermarket “Chevelle drop-base” air cleaner I was running on my Street Avengers fits the Stealth throttle body just the same. That is, I have to run a 1/2” spacer between the throttle body and the base of the air cleaner just like I did on the carburetors. Also, with the throttle extension installed the throttle crank still clears the air cleaner base. Essentially, the clearances on the Stealth throttle body mimic that of a standard Holley carburetor.

If you have a nice braided inlet hose setup for a dual-feed Holley, it may or may not just screw right onto your new throttle body. My inlets on the Stealth are spaced about 1/2” farther apart than they are on the Street Avengers. ALSO, most Holley inlet extensions use a female AN fitting. The Sniper uses a male inlet fitting. And on that subject, the inlet fittings that Holley installs are too short. When you tighten up the supplied fuel feed lines the fuel hose is pulled very tightly against the throttle position sensor plug. Horrible design. I used a pair of -6AN male to -6AN female adapters which were plenty long enough to give the fuel inlet hose enough clearance.

AND... on the subject of fuel hose, you’ll need about 10‘ to 15’ more than what Holley gives you in their kit unless your car is an SS and you can use the factory 3/8” hard line. Mine is, but even still I used every inch of the 25’ that they supply. If your car has 5/16” fuel lines plan on spending money on more feed/return hose or hard lines.

Regarding the plumbing, for some reason Holley supplies one-too-few barbed hose fittings. I needed one more -6AN female to 3/8” hose barb fittings than Holley includes. As it turned out, I added a 2” pigtail to the tank end of my return line so that I could disconnect the return if I had to drop the tank in the future. Otherwise I’d have to fight with the fitting while trying to balance the tank in place. So instead of being short just one fitting, I ended up using two additional hose ends and one each of -6 male and female fittings. Also, had I not done that I would have come up 2‘ short on fuel hose.

That’s all I can think of for now. I’m very happy with the system. I just wish I had been prepared to buy these few little add-on‘s when I first got the system. It would have saved me some time. Hopefully this long winded post saves someone else a bit of time when planning out their system.
Thanks for the write up on your suggestions on the Sniper EFI. I also have a 68 (327, 275HP with glide numbers matching), that I just finished installing a Sniper 550-110. I did go with a in tank pump set (Tanks) and ran Earls Vapor EFI hose as the return. I do have some tuning to do on it and have not yet driven it but it does run. I do have a GM HEI distributor so I had to install an offset base so that I could run a 14" open element air cleaner for clearance. It does have a dropped base but there are no clearance issue. I am having some problems with high idle but I think I have a bad CTS (reads low err) so I will be swap that out in hopes of correcting the problem. I am having an issue with the throttle and kickdown linkage (stock for now) as well as return throttle springs. Would it be possible for you to post pictures of your set-up with the throttle and springs? You mentioned the Holley throttle extender. Can you picture that also? I will not be using the ten pin wire harness not the crank sensor plug. Don't know if you are but if not, will you remove them (cut them off?) or just tie them up out of the way?
Thank you
Al
 
#6 ·
Any4xx,
Thanks for the quick reply and yes, I would very much appreciate pictures of the linkage when you can get around to it upon your return. As I mentioned, the car is drivable but I will not put it on the road (register it and get plates) until next spring so no rush. Thanks also for the links to the Holley products. I don't want the unused wires/harness and plugs in the engine bay if I am not going to be using them.
Al
 
#7 ·
Thanks for sharing this. My 87 Caballero build is in progress. I have the Sniper EFI, distributor, coil and controller. I have a Blueprint roller cam 350, so all of these new parts $$$ concern me. I appreciate what you posted, to help me protect my investment.
 
#8 ·
Thank you all for sharing this information, I am contemplating the change to the Sniper set up as well as the Holley 650 is very thirsty and cold blooded. I just purchased this 72 350 SS and it arrived here in NM 2 days ago and I am giving it the TLC it needs and researching it's needs. It runs well and someone has made unknown upgrades to the motor such as aluminum heads, headers, Edelbrock manifold, likely a cam upgrade as it has a bit of a lope and larger oil pan. Have you noticed any improved driveability issues such as better cold/hot starts or improved fuel mileage?
 
#9 ·
Much easier starting in the morning. No playing around to keep it lit. I have not measured, but I am certainly getting better fuel mileage.
I wish I knew you were in NM. I just spent the last week at my place in Rio Rancho and was bored more often than not.
 
#10 ·
Thanks for the information, that's what I was hoping to hear. I live in Alamogordo and have just permanently moved here from Sacramento CA. I am a big fan of the 72 as when I was a kid I learned to drive (and wrecked) my parents 72 Chevelle as well as a lot of other teenage first's in that car. I am going to find or build an additional garage to store and work on my car's.
 
#11 ·
my dad spent a few tears living in Alamagordo, "testing it out", as he is retired military. he left (~2010) saying the problem was the water supply (snowmelt) and with more people constantly moving in.
I used to travel to Albuquerque for years to visit Grandma (my mother grew up there), but that stopped 20+ years ago. Last trip thru we went thru Capitan and stopped off at the Smokey the Bear museum and park.
 
#20 ·
I had a Sniper Stealth 4150 installed last week with the Holley (AKA Tanks Inc) EFI conversion tank. The Walbro 255lph (GSS430) pump that comes with the tank is loud. I'm replacing it with a Deatschwerks DW200 pump with a different design.

I wish I'd have known about the throttle extension. However, I solved my hard pedal issue with a new, albeit, expensive, throttle pedal Lokar part# XBAG-6205 for the black; BAG-6205 for the silver. The Lokar peddle looks cool and replaces the factory throttle pedal; It feels like a new car.

I had an issue with a low stall factory converter in my TH-350 transmission. The car would die when going into drive. My shop recommends a 2800-3000 stall converter since they just had a C10 truck with the same problem. I'm expecting the new pump and converter to be in by Friday this week.
 
#21 ·
I had a Sniper Stealth 4150 installed last week with the Holley (AKA Tanks Inc) EFI conversion tank. The Walbro 255lph (GSS430) pump that comes with the tank is loud. I'm replacing it with a Deatschwerks DW200 pump with a different design.

I wish I'd have known about the throttle extension. However, I solved my hard pedal issue with a new, albeit, expensive, throttle pedal Lokar part# XBAG-6205 for the black; BAG-6205 for the silver. The Lokar peddle looks cool and replaces the factory throttle pedal; It feels like a new car.

I had an issue with a low stall factory converter in my TH-350 transmission. The car would die when going into drive. My shop recommends a 2800-3000 stall converter since they just had a C10 truck with the same problem. I'm expecting the new pump and converter to be in by Friday this week.
 
#22 ·
Maybe call Holley about your issue before going and dumping a bunch of money into a stall? Sounds more like your shop is trying to make a quick buck than actually get your car running correctly. Holley's customer service is awesome and can point you in the right direction first.
 
#24 ·
FUEL PUMP

I definitely recommend Deatschwerks fuel pumps. They are way more quiet than the Walbro pumps. DW200 pump was an exact replacement for the Walbro GSS430 that came with the Holley/Tanks, Inc. EFI conversion tank. Walbro pumps use a gerotor gear that's metal on metal. Deatschwerks uses a composite impeller.
 
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