Putting 72, 350, 4 speed car back together after a resto mod rebuild. The 350 motor has a decent 585 lift cam, 109LSA. The aftermarket aluminum heads have no crossover for the choke so now I'm looking at rebuilding the "rebuilt" Quadrajet, adding an electric choke and making a lot of modifications just to get it work with this motor. The Quadrajet core that I have is not the best. I'm considering going with an EFI system and it looks like the ACES Fusion or Killshot 2 system may be a better choice over the carb for a little more money. Any one here using the ACES EFI system on a modified motor? Single plane or dual plane intake? The installation will not be an issue for me as I'm still in the process of putting the car back together. The motor has been ran and it's currently sitting on a run-stand. The original carb was terrible so I need to make a change in the fuel delivery area.

 

I have an ACES LS top end kit that I haven’t used yet. The quality seems good, but their customer support could use some work. I emailed them in January about transmission controllers and have yet to get a response from a real human being.

That being said a Quadrajet will need quite a bit of work done to work well with a camshaft like yours that produces very little vacuum. I would be leaning towards EFI regardless. The Killshot 2 TBI system seems to be nice and for a good price too. And yes, it will work best with a single plane intake.

 

I've heard realitivly good things about Aces EFI. Myself I run a different brand. And I couldn't be happier. No a throttle body EFI system won't give you more peak power.
But it will give you much better drive ability.
Hit the key, it's running, back out and go. No carburetor can really do that. High gear at low speed on a steep hill? Carburetor, down shift. EFI, drive on.
Getting it all dialed in? Yes there is definitely a learning curve with EFI.
However, that's a fair wack of cam you got there. I don't think I could dial in a Quadrapuke no matter what.
Run a intank pump if you run EFI. No fuel control module or in line pump. Spend the time to dial everything in. Don't even begin to believe the self tuning lies. You will need to get it dialed in. The wideband can only adjust the main tables.

 

If you haven't bought any of the parts then you might consider the Holley Alternative EFI systems. I have a Holley Stealth Sniper on my 427 and it runs great and the car starts very easily now.

I bought my EFI system from a company who gives you two years of post-sale (great) customer support. This is important because they will get you up and running. This kind of support "made" the sale for me. I also budgeted $2500 and came in way less at ~$1700 for the entire system including two years of tech support. The people that work there are Holley Trained EFI Technicians and they know the systems inside and out.

Holley has been building quality fuel system components for longer than I can remember. I trust them and the people that sold me my EFI system to get me a top notch fuel system. I have been very happy with my Holley EFI system!

The people that sell Holley EFI systems with 2 years of post sale support are: EFISYSTEMPRO.COM and they offer great prices with incredible customer support. If you need more convincing take a look at Holley's EFI software which allows you to custom setup your system and make adjustments if you want to.

The idea of using an In-tank fuel pump will clearly make it quieter inside the Corvette. I have the Holley OEM In-Tank fuel module which has the pump and fuel pressure regulator inside the fuel tank. It took about 1/2 hour to install the fuel system requirements for my new EFI system.

Good Luck with your EFI system and may it be an easy swap for you!

Best regards,
Chris

 

Sounds like going to EFI is the new standard. As far as using an in-tank pump, I have already installed a new fuel tank, sending unit and lines. Inline fuel pumps make a little more noise but can be changed relatively easy if needed and the cost will be much less than buying a new tank, sending unit and fuel pump assembly. With the exhaust on this car, a little fuel pump noise will likely not be heard. I wanted to stay "old school" on this build but drivability is also important. I know the auto tuning is not gonna work for this motor but was looking for those who have gone through the tuning process to gave an idea of their progress and satisfaction with owner/driver tuning. I have tuned my Harley via Bluetooth, tuned my C6 LS3 and transmission along with a few other fuel injection tunes The Aces units will allow a hall effect switch in the ignition system to be controlled by the controller or just not use the ECM and run the basic timing process with vacuum and mechanical advance. The other EFI units have stated that I have to use one of their distributors or other add on ignition parts. I want to keep the old tach drive distributor so I replaced the points with a Petronix hall effect switch.

 

I run Aces Killshot throttle body on my 365 HP original engine in my '64. Unless you are familiar with EFI tuning and are very patient go with a carb. I have installed Holley and Megasquirt. I gave up on trying to figure out Aces tables and software. I control Killshot with a Microsquirt controller. Carbs are much easier. Ditch the Qjet. Many more parts are available for a Holley carb. JP

 

Hello again Hydrasport,

The Holley system uses a OEM Fuel Module and that fits inside your original tank. Because my tank was in good shape I did not have to replace the tank at all. I simply pulled the plug from the bottom and pushed the new parts inside the fuel tank and re-inserted the plug. The fuel pump, fuel pressure regulator and fuel level are all on the same piece which included a piece of Holley's Hydra Mat which is amazing stuff all by itself. The entire fuel system was done in minutes. I do not have a return line which makes it simpler.

Prior to this I was using an external fuel pump and regulator by Aeromotive and it was nice. Even rubber isolated you could hear the pump over the other parts. I then went to a PWM Aeromotive fuel pump controller which quieted it down a good deal but not completely. My Holley in-tank equipment is as quiet as factory stock parts normally are on street cars.

The Holley EFI software is another very important feature that helped convince me. This software they made is amazing and allows you to custom set up the EFI system, it is professional grade. If you need a pro to help you they can because this software is able to control anything with the EFI system.

Another nice system is the Edelbrock Pro Flow system which is a multi-port injection with 8 injectors. It is better than the options out there, at least in my opinion other than the Holley equipment of course.... I wish Holley offered a version of the Pro Flow using their equipment, I want a multi port system and have to settle for 4 injectors currently. The throttle bodies they make are top notch and well made, the system's controls do "self learn" as you go after you set up all the parameters before hand. The more you can tell it the better it will control right from the start.

I am still using my MSD Billet Distributor with the mechanical tach drive as well as a MSD6AL and Blaster 2 coil. I have seen no reason to change away from the MSD system. MY MSD does the ignition and the EFI system controls when to fire the spark. My car came with the K66 Transistorized Ignition system and those parts were removed to be replaced with the MSD parts. I simply locked out the base plate and removed the vacuum advance on the distributor and it works just fine with the MSD parts. My K66 parts are in vacuum bags on a shelf.

 

Aces EFI on my C3. Great system, went through the startup wizard and car fired up on the first crank of the key. Stay with carb if you don’t have basic understanding of engine concepts, electrical skills and/or have trouble reading instructions.

 

The intank pump isn't so much about the noise as it is about reliability. Seriously reconsider running a inline pump.
Absolutely no need to replace your tank just to put a pump in. Holley makes an excellent drop in setup as do several others.
I run the Summit MAX 500 EFI system. So do a couple of my friends. It's affordable stand alone EFI. Does NOT control spark. Only fuel. The ECU is NOT mounted right on the throttle body. But rather where you put it.
Might be something to look at.

 

I have the MPFI SBC kit from ACES and so far so good. Only have about 500 miles on a new 400 SBC crate engine but the EFI has been pretty good. They have been making it better since I bought mine too, but my V1 of their ECU has a little less tuning features than a holly LS ECU. I know their new stuff has a lot more going for it. Also I have had good experience with their technical support. Over all very good for the money.

I would %100 suggest a professional tuning, unless you plan to get deep into learning to tune EFI. The automatic learning advertised by all these EFI companies is BS. It will run fine, but you won’t get everything out of the engine without a good tune.

 

In your first post it sounded like you are still on the fence about whether or not you want to go to efi.
My $.02 worth is keep it simple, stick with a carb.
I thought about going with efi on my 496 big block.
My engine builder and I discussed all the pluses and minuses.
In the end I stayed with what has always worked best for me.
I’ve always run straight carbs, no choke, mechanical secondaries and never gave them a second thought.
All my boats, classic cars and motorcycles have been carbureted (except one Harley and one Ducati).
I am old school and in my opinion there is just less to go wrong with a good old carb.

 

I am an Engineer and I would like to offer a different opinion about this. I have been tinkering with carburetors since the early 1970's and after all of my experience I would say the EFI systems are "ready" for Prime Time. I have a Holley EFI system and it was set up by a person who understands EFI systems and it went pretty nicely. I have not had to use any professional help to get my 427 running smoothly in my C3.

Carburetors are not as easy to set up without lot of experience and the right tools. I never got mine "perfect" until the advent of a Air/Fuel ratio gauge and then I was able to dial in carburetors much more easily. I have had custom carburetors that were set up before they were installed but that skill is more rare anymore.

With the air/fuel gauge I can verify that the EFI system is working properly and the car drives great. The one thing I miss is the the low fuel pressure of carbureted vehicles. Having a leak when you are dealing with 60 psi will make a mess and potentially a fire really fast. All the reason to be even more careful with the pressurized fuel lines! I wrapped my fuel supply line inside a fire proof jacket and then put an insulating sleeve over the fuel lines and jacket and ran it from the fuel tank to the engine itself. Cooler fuel doesn't boil away so easily and it makes more horsepower as well.

 

I really don't care if it's a Carburetor or EFI if you don't have experience tunning them you will need to find somebody who does. Don't go with the "self-learning" sales pitch of modern EFI. That's the first thing they teach you that isn't true when you go to Holley EFI School. If you have a mild stock engine both a Carb and a EFI will drop on and work right out of the box. If you have something with little Vacuum neither is going to work and you will need a tuner. If you good with your hands assembling parts and have some grey-haired grandparents i would go with the Carb. If you have some pretty bright grandchildren that are good on a laptop I might go that route. Better yet figure out who is going to tune it first and then go with their recommendation. If I had to pick one over the other, I would go with the EFI as I think tunners are going to be more accesible and hear to stay, after all, GM hasn't put a Carb on a vehicle in 39 years.

 

I can recommend Bryant Stilwell @ Nomadic Dyno. If you can do the mechanical work and install he can provide remote tuning services for both Holley and Aces EFI.

https://www.nomadicdyno.com

 

I've had a killshot for a couple years but found out the hard way it wouldn't work with my cowl induction setup so I bought a ks2 which will clear any drop base air cleaner and have the progressive throttle linkage. I've taken next week off work to hopefully get the car back together and get it installed before the Iola car cruise event I hope to take it to in July. I'm hoping to get it tuned by someone after getting it installed.