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Need some EFI advice

What EFI Model Would You Choose?

  • Sniper 2

    Votes: 6 66.7%

  • Sniper 2 Quadrajet

    Votes: 0 0.0%

  • Aces Killshot

    Votes: 1 11.1%

  • Factory GM TBI Kit

    Votes: 3 33.3%

  • No EFI, Just get any Carb

    Votes: 0 0.0%
  • Total voters
    9
  • Poll closed .
Operator238

Operator238

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1985 K5 Blazer 4x4 350ci


I see a lot of kits out there run external fuel pumps, if I want to do an in tank pump, would I need a new tank? I had to do this in my chevelle and convert the fuel lines. Anyone running external? I’d imagine they’d get hot with prolonged use.

Would you rather have:

Sniper 2 Quadrajet Model
Ace Killshot
Factory GM TBI Kit

My plan was to go with a Sean Murphy Induction carb. I had two on order and they decided to recently close their doors.
 
No idea what your objective is. I've experienced good luck with the GM 350 with a factory carburetor or EFI.
 
I looked around at the sea of $1k TBI type EFI kits for a while and, whether researching here, the 'net or FB, I found reviews were 50/50 on virtually every kit. The problem seems to be the design where the ECM is built in to the throttle body so it is exposed to heat more so than a remote unit. It's really a "get what you pay for" thing so the more you spend (probably) the better the kit.

Fwiw, a couple of months ago @83ChevyK5Blazer had a SMI qjet for sale but I don't know if it sold.
 
Operator238 said:
1985 K5 Blazer 4x4 350ci


I see a lot of kits out there run external fuel pumps, if I want to do an in tank pump, would I need a new tank? I had to do this in my chevelle and convert the fuel lines. Anyone running external? I’d imagine they’d get hot with prolonged use.

Would you rather have:

Sniper 2 Quadrajet Model
Ace Killshot
Factory GM TBI Kit

My plan was to go with a Sean Murphy Induction carb. I had two on order and they decided to recently close their doors.
Click to expand...
In terms of the pump:

In tank of the quietest, and can utilize all factory parts and pumps. Then decide what lines to use
Factory EFI tanks are different

I would also be 100% adamant about using and external relay for the pump. Under no circumstance would I trust the ecm internal relay to be enough, and has been one of the issues with the Sniper
 
edelbrock pro flo 4 hands down . . . worst 3 months and 500 miles of my 1 build was with a holley sniper .

and as far as intank pump its easy . 87-91 blazer tank and sending unit with acdelco ep381 pump swapped on sender and high pressure line and good to go . my build has been 4 years now running the gm fuel tank and sender stuff like this . and parts are most any parts store vs full custom swap around stuff .

there is a LOT of great info and stories in the INJECTION SECTION here just for efi stuff .

also if tbi gm based kit ..... HOWELL EFI .
 
CT-BLAZER said:
No idea what your objective is. I've experienced good luck with the GM 350 with a factory carburetor or EFI.
Click to expand...
Honestly, I hate having to crank the engine over several times because the floats are already empty. This modern fuel evaporates so quickly. I guess one positive it gets the oil moving in the engine before it runs. I was thinking oh just getting an AVS2 and be done with it. Sean Murphy said if he had to buy an off the shelf unit it would be a QFT carb.
 
Don't get any of them with the ECU built into the throttle body. I can't see going EFI but still running a mechanical distributor, either. You'll be over $2k just to get the basic system in that case, which is getting into LS-swap territory (I know, these things snowball and prices vary wildly...) (EDIT: Maybe the aces system comes in cheaper than that, but I don't see anywhere about whether the timing is controlled by the ECU or not.)

That makes the GM TBI the best of what you've listed, especially in terms of bang for the buck. Nothing wrong with it as long as your engine is stock and you're not looking for big performance (keep in mind the 350 got a 25hp rating increase when the TBI replaced the Q-Jet - no idea how accurate those numbers are).

The fuel tank is not that big of a deal, IMO. The spectra replacement TBI tank has been discussed here and it's neither terrible nor expensive. Figuring out fuel lines takes more thinking, but that's stuff that has to be done no matter which EFI system you go with.
 
Since I don't run gasoline powered vehicles anymore, I'm not used to its quirks....

Newer vehicles are EFI with electric fuel pumps in the tank, which are great for easy priming should you run out of fuel.

If dry carburetor floats are a. Issue, why couldn't the vehicle be outfitted with a low pressure electric pump in the tank?

All I'm familiar with are older ( carburetor V8's). Vettes from my teens. Cars were already Fuel Injected when I started to drive.
 
Just gonna add an option to this convo, I've been running the Summit Max-efi 500 for close to 4 years now and it's been great. Sure, it's made by FiTech, but it is Summits design.
The ECU is separate, and I have mounted it on the firewall but I will probably move it in the cab at some point.
I have had no problem running the factory style HEI with this system.(not EFI controlled )Screenshot_20240220-085633.png
My biggest issue was getting a good fuel pump to work with the EFI, as it needs 58 PSI to run. The best solution I found was a Holley in tank fuel pump made for my saddle tank which has worked great for a year and a half so far.
 
cheavyk10 said:
Just gonna add an option to this convo, I've been running the Summit Max-efi 500 for close to 4 years now and it's been great. Sure, it's made by FiTech, but it is Summits design.
The ECU is separate, and I have mounted it on the firewall but I will probably move it in the cab at some point.
I have had no problem running the factory style HEI with this system.(not EFI controlled )View attachment 468239
My biggest issue was getting a good fuel pump to work with the EFI, as it needs 58 PSI to run. The best solution I found was a Holley in tank fuel pump made for my saddle tank which has worked great for a year and a half so far.
Click to expand...

This is cool, I didn't know there was a kit like this with a separate ECU.
 
Operator238 said:
1985 K5 Blazer 4x4 350ci


I see a lot of kits out there run external fuel pumps, if I want to do an in tank pump, would I need a new tank? I had to do this in my chevelle and convert the fuel lines. Anyone running external? I’d imagine they’d get hot with prolonged use.

Would you rather have:

Sniper 2 Quadrajet Model
Ace Killshot
Factory GM TBI Kit

My plan was to go with a Sean Murphy Induction carb. I had two on order and they decided to recently close their doors.
Click to expand...

If bone stock 350 is all that's in your future, I'd go GM TBI and not think twice.

If any mods are something you'd consider, I'd strongly suggest a system that is much easier to adjust for the modifications. TBI is most definitely not.
 
cheavyk10 said:
Just gonna add an option to this convo, I've been running the Summit Max-efi 500 for close to 4 years now and it's been great. Sure, it's made by FiTech, but it is Summits design.
The ECU is separate, and I have mounted it on the firewall but I will probably move it in the cab at some point.
I have had no problem running the factory style HEI with this system.(not EFI controlled )View attachment 468239
My biggest issue was getting a good fuel pump to work with the EFI, as it needs 58 PSI to run. The best solution I found was a Holley in tank fuel pump made for my saddle tank which has worked great for a year and a half so far.
Click to expand...
this is nice I may have to look into it. No vacuum advance for you ?
 
the edelbrock pro flo 4 is separate ecm from the start way back in the early pro flo 1 days .

yes as said a good efi setup like pf4 will cost 2k . so if your not dead set on sbc or bbc look at LS for not much more you get min 350hp tuned stock guys and 15-18 mpg all day on highway .

with the other stuff you need to know how to tune or have a person who does near you .
 
If you're staying stock engine wise, stick with GM style TBI. If you want anything more, Holley Terminator Stealth or Edelbrock proflo.
I ran the FAST EZ EFI 1.0 for about 10 years and while it was good and better than a carb, it had some quirks and tuning it was limited. It was one of the first self tuning bolt on EFI kits which was revolutionary at it's time but now there's way more options on the market.
 
Holley makes an OE style in tank fuel pump.
You can get different sizes.
For example the 31 gallon tank would be Holley 12-333.

The other size tanks have a part number 12-33??

FWIW I would get a new tank anyway if it’s old. They’re still reasonably affordable and don’t have years of funk in the bottom.
 
So if I were to use this, do I just plug all my sensors back? Currently the previous owner put an Edelbrock 1406 and non factory distributor.

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