I am looking to convert my 70 Challenger to efi. It is just a street car with mild 440 stroker.
I plan on getting the Hyperspark distributor and the retrofit fuel pump. Is the Terminator Stealth Throttle Body Fuel injection System worth 2x the cost of the Sniper ?
Is the Sniper unreliable since the EGU is part of the TB?

I have a Sniper on my Challenger. It has a 511 stroker in it. The main issue I have had is RFI. The Terminator has a remote ECU that can be located away from the engine bay in a more friendly RFI environment.
That being said, I have gotten mine to run very well after cleaning up some wiring and changing to a Denso alternator.
I think the Terminator has more inputs and outputs that can be used.
Good luck, which ever way you go.

I have a Sniper on my '65 Coronet. It works just fine with the Hyperspark ignition setup. I've written a few magazine articles on the install as well as shot some short youtube videos. Proper wiring is critical. If you don't have a decent understanding of EFI wiring then you'll want to get some help with the install. The Holley instructions don't go into much depth and a lot of "old school" hot rodders don't understand how important wiring layout is for a microprocessor. If the wiring isn't correct the Sniper won't run.

https://www.motortrend.com/how-to/holley-hyperspark-install-tune/
https://www.youtube.com/watch?v=64DrLMCLULA

I have swapped modern engine in an old car(71 510 w/ 97 KA24DE) and replaced factory ecu with an AEM standalone ecu but didn't tune it. All the wiring is new so far I have not had any issues
I know about some of the RFI issues and importance of good grounds. When I was a tech 30 years ago
we had fun chasing down gremlins caused by bad grounds. My car has the a modern alt and Firecore wires but the wiring is mostly original. I was interested in the Terminator Stealth for the ability to upgrade to “HP” ECU specs with a free online software download and keeping the ecu out of the engine bay for reliability. Not sure it is worth 2x cost to me. I would like to learn how to setup fuel and spark tables.

It really depends what you want to do with the system. The Sniper is a fully featured entry level system. It can do a ton of stuff but it is limited on extra channels. The Super Sniper has three channels of info and the Sniper XFlow is CNC machined with larger injectors for more power so those are two "in between" options. I wouldn't buy a Terminator unless you really need some of the features. Rich at FAST Man EFI is a board member and a Holley dealer. Call him and ask him which one he recommends. He'll provide you with some information and get you a decent price on the system that you pick. He can also provide you with an online EFI training class.

Have you considered the MSD Atomic throttle body EFI? The control module can be mounted inside the car. I have installed a couple of these and they work great. $1268.95 at Summit. Also since you can mount the control module inside I don’t believe they will have the RFI issues like the Sniper. You still need to have good grounds. They have the same capability as the Sniper. I had a Fast 2000 on the 512 in my 69 Bee. Loved it but they are expensive.

No but I will look into the MSD Atomic EFI.
Also will call Rich and see what he recommends.
Thank you.

I think the MSD Atomic is dead now that Holley owns MSD.

Don’t think so. The are still available from Summit and Speedway Motors. Also still listed on The Holley web page.

https://www.holley.com/search/?q=Atomic%20EFI

The 1268 kit lacks a fuel pump, also not sure you get the wideband with it either, guessing not or it’d be mentioned.

I had an early Holley projection system on a 440. It worked well enough, but didn’t have the o2 and the mpg wasn’t good. I had a truck with a TQ that ran every bit as good as that system did. Only way I’d consider efi now is with a sensor. I think the options now are cool, but being older and wiser I see them all as being more complication and small improvement for an occasional use car. Occams Razor.

Haven’t seen a throttle body efi that doesn’t have an o2 sensor yet. Most don’t come with a fuel pump. If the do it’s us external. They really should have an in tank pump. External pumps work but I wouldn’t recommend using one. I seen a huge fuel mileage increase when I put the FASt 2000 on my 512 stroker. Having better control of the air fuel ratio helped but I believe having the ability to program the timing curve has the most influence on MPG.

The Projection had an O2 sensor as an added cost option, not included. FWIW, it was a horrible setup. Put the 2Di on my Diplomat, it ran after a fashion, sprung for the O2 option, no difference in function. It did teach me a lot about how NOT to do a TBI setup.

I am using a stealth sniper and love it so far (Demon with a 451). Thus far it has only been "tuned" using the learn mode. I have no experience with the Terminator system.

The Atomic is dead, they are just selling what is left on the shelf. The Atomic 2 is basically a Sniper in disguise.

I hear ya. Everyone I know running a Sniper is happy with it. I’m now debating between the Atomic or Sniper. I like the Atomc only because the control module can be installed inside the vehicle. On the other hand I like the fact that you don’t need an ignition box with the Sniper just the harness to the coil and distributor. Anyone using the Holley Sniper EFI HyperSpark Distributor? This is for a street only application in a Federal Motors Truck Rat Rod.

No technical support for the true Atomics.

A friend installed one a couple of years ago on his LS turbo '70 Chevelle and it was quickly obsolete. He pulled it all off and recently installed a Holley Terminator. Crazy how much he spent on the Atomic originally just to have it not supported shortly thereafter.

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Now that I think about it you are absolutely correct. This makes my decision much easier. I’ll be going with the Sniper and the HyperSpark Distributor.

I'm using their entire kit with the distributor, ignition box and coil. Was fairly painless to setup and I was already aware of head clearance issues thanks to Andy's article. I'm looking forward to fine tuning the spark map this spring.

The higher cost atomic on that list comes with a fuel pump and mentions an o2. For 1268 bucks it appears you don’t get either.

Well I had an interesting morning. Loosing my shop. Guy who was working on the car is out of the area, job shortened my hours and the union is looking to strike on top of my surgery may not be fully covered by my insurance. The fuel injection will have to wait. I will reach out to Rich as he has done a couple buddies of mine cars and looking like the Holley Sniper is going to go on (when the funds come available) will be going one one of the cars. Thank you to everyone who responded to my question and had great advice for my projects.