Good Afternoon All,

I am planning to upgrade my 1969 to fuel injection in the next few months. It currently has a fairly low mileage 383 and is carbureted. I have a 73 and 75 that I have put LS engines in and I have become sold on fuel injection. Not ready to do the LS swap in the 69 but would like to take the baby step to FI on the existing engine. I know what needs to be done for the tank to get 58psi fuel to the engine, what I am looking for is the parts I need on the engine, I would like to have the distribute controlled by an ECU, so I think I need this:

https://www.summitracing.com/parts/fif-30005

I was hoping to use an HEI distributor with mechanical tach drive as part of this setup if possible.

Any advice is appreciated.

Scott

 

Personally I'm partial to the Holley EFI systems because they seem to keep supporting them longer than others. But I've never used a FiTech/FAST/Edelbrock/etc so can't say there's anything wrong with them.

Consider sequential port injection if you have a beefy cam as it will idle better and have better drivability than TBI.

As for the distributor just get a 75-77 electric tach and swap your old face plate over (or buy a new face plate). I got a face plate for a '69 350/350 with a 6K redline and the correct early green numerals. Think I paid $30 for it.

 

Thanks for the feedback, I have a roller cam that is not too wild. I like your thoughts on the Tach. I am leaning towards multi-port, the Edelbrock setup seems comparable but for a lower price than Holley and I would think they would support it for a while.

 

I assume you are talking about the ProFlo 4 system from Edelbrock. If that is correct, then you are going to be using the supplied distributor. I did this on my 71 LS5. At the time of installation, my tach drive wasn't hooked up because I hadn't installed a tach drive HEI distributor. I bought the electronic tach conversion kit and installed it when the rest of the install was taking place. Now I have a tach. The ProFlo 4 utilizes the distributor, controlled by the ecu, to smooth out idle and allow control over advance curve setting. It is nice to be able to customize the advance curve, via the app on my cell phone, through the ecu. Mine is the 4150 manifold versus the log. It keeps the look I was after. Unfortunately, I had a hydraulic flat tappet cam lifter issue that wiped three cam lobes, and I am now waiting for roller cam kit to arrive. Ordered it back in October. New best guess is February. Somehow, I doubt that it will get here then. Hopefully before the weather gets nice. I don't have any regrets about buying the ProFlo 4 system. It does everything I need and I no longer have fuel distribution issues.

 

Hello there ScottEwine,

I have a Holley Stealth Sniper with a Holley OEM Fuel Tank Module on my 427 and they work great. I am getting ready to connect the timing to the system as well so the Holley Software will control both fuel and timing on the 427. I have a mechanical Tachometer so I needed to keep my MSD Billet Pro Distributor with the tach drive on it.

The Holley OEM Fuel Tank Module was the easiest part to install and took less than 1/2 hour. The electric fuel pump, Fuel pressure Regulator and the Fuel level sending unit all fit inside the fuel tank along with the piece of Holley Hydra Mat that attaches to the end of the fuel pump.

If you are concerned about parts fitting properly then you might look into your options. I purchased my EFI system thru EFISYSTEMPRO who is located in Florida and will give you incredible support for 2 years after the purchase. The guys there know their EFI systems and can help you if you have any questions. I actually thought very carefully about the ProFlow 4 system as it looks like a nicely put together part. In the end it was "Who will help me if I run into problems" that won me over to the Holley Stealth Sniper. I had planned on buying a new tank but the guys at Efisystempro were able to sell be a complete system for less than I had budgeted for the system.

I saved Hundreds over what I expected to cost and the system is great for a throttle body.

 

I am currently looking at the Edelbrock pro-flo- 4 4150 style and its rated for 675 hp I think either the holley or the edelbrock are really good for the cost did you buy it in kit form or as individual parts also fitech has a set up similar to the pro flo but there customer service sucks.

 

The Electric Tach is the hot ticket. Ever since I went to an electric tach everything else has been easier.

I pondered getting one of those holley electric fuel pumps that come in from the bottom..... sounds pretty wonderful, but I had time so I modified a Stainless Steel 1982 sending unit and made a pump support for a cannister-pump that comes in, and out, from the top. I did this because I did not want to deal with emptying the gas tank to replace the electric fuel pump (if it ever came to that).

 

I originally bought the Holley Commander 950 port EFI kit back 20 years ago. 10 years ago I got the Holley HP upgrade kit that had a new ECU and harness. I was able to re-use the manifold, throttle body, injectors, and all sensors except O2. I don't know about other brands but I was impressed Holley makes upgrade kits for their older systems.

 

I have a tech guy at holley and sent me a really nice quote that matched summit racing and then discounted quite a bit off and will discount even more if I buy the fuel system through him and your holley hp upgrade kit is a nice kit and not cheap and I noticed your running a drop base air cleaner and that seems to clear just fine the intake I would be running is 5.28'' tall at highest point in the back of manifold.

 

I like the Holley Stealth Sniper EFI system the more I work on it. It is a well designed system and when you buy the parts together you should get a better deal.

On my 1968 I am still using a MSD Billet Pro Tach with mechanical tach drive but don't really "need" the cable with the Tach supplied on the Holley Handheld. I want one of Holley's 6.7" Touch-screens mounted on my dash in the center console. I just love their display tricks and their software is quite powerful with a lot of potential. It will control the timing, fueling, cooling and my Water/Methanol Injection system all to make and keep the 427 a "happy" 427.

The Holley Stealth Sniper fits on my 427 with an Edlebrock Performer RPM Air gap dual plane intake using a factory L88 Hood. I am also using the same intake parts as shown above by zwede in those beautiful pictures of the L88 parts on that Red Corvette. It is a bit snug using the factory seals on my C3 but still seals to the hood effectively. The stealth version is designed to look more like a carburetor and it does fit nice and snug under the drop base that I last used on a Double Pumper. It might be the shorter of them, it is a bit taller than my old Holley Double Pumpers but works great. It even starts in the cold weather now....

That Red C3 is a beautiful example of what a big block running the Sequential Fuel Injection looks like. I was wondering what it would look like under the L88 parts. Is the cold air intake still functional? How does it drive? Is it worth the difference over a normal throttle Body system? My Holley dealer is more than happy to try and sell you anything you can dream of. That is a really nice installation! Thanks for sharing it with us!

 

Thanks!

Absolutely. I did have to machine the top of the intake down about 1/2" to make it fit. I also made an angled spacer under the aircleaner base to get the right tilt forward to match the airbox in the hood. In retrospect I should have just machined the intake at that angle.

I never had TBI on it so can't answer how it would drive with TBI. Going from bank-to-bank EFI (the old Commander 950 I had before) to sequential did clean up the idle quite a bit though. My cam is not that big; 231/239 degrees, 110 LSA. I think with a mild cam you wouldn't notice much difference between TBI and sequential. But if you have a performance cam sequential is probably going to make a noticeable difference.

 

What forward tilt are you referring to on your L88 hood air box? Mine looks flat and seals well. I did have to plug the Draft Tube hole in the air box to keep hot air from being pulled in. On my hood it comes down level onto the carburetor base and seal. With it working I get nice cool air heading for the combustion chambers and that is a great benefit when running high compression.

Removing the 1/2" from the top of the intake might be a good idea on my C3 as well. I want to have a professional, drill and tap my intake as well for the Water/Methanol injection system nozzles. I guess I will pull it when it warms up a bit later in the spring.

My wife had a GM Pickup with a TBI system and it worked great for 200k miles. On the Corvette I am still up in the air. My system keeps the A/F ratio right on the money and that is significant. I want to verify the A/F ratios on the UN-monitored side as well before I assume all is going well.

Once at Corvettes@Carlisle a crew from Speed-Vision started filming my Corvette. They had assumed that it was a real L88 since it had some of the right parts (along with a heater and radio). They were surprised to find that I drove it there and was driving it home. My C3 is painted the 1969 Color Daytona Yellow and is a convertible. I have seen the episode play online with my Corvette being scrutinized by their cameras. My engine looks clean and straightforward but does not have the little Snowflakes on the cylinder heads like a L88 would. I told the crew that it was a L88 Dupli-car for all practical purposes and that it is running the L88 Pistons and compression. I have never mis-represented my Corvette as a factory L88 Corvette. I do have several parts from a real L88 on my Corvette.

 

Many intakes like the Edelbrock RPM for carburetors tilt the carb down a bit in the front. The Holley EFI intake I have didn't so the front of the aircleaner base was too high up.

 

Beautiful. For the sequential port injection, can I ask how you implemented the cam position sensor? My engine builder has suggested port injection. Haven't selected a cam. Thinking of something in the 240 degree range at 0.050 lift, hyd roller.

I noticed a fuel regulator snuggled up against the water pump. Holley, Aeromotive? The fuel system I'm putting together for my 70 has an Aeromotive A1000 fuel pump, Aeromotive filters, EFI regulator, and a speed controller. The reguator has a conversion kit to rebuild it for carburetors.

My 68 ZZ4 has a HEI distributor with a mechanical tach drive. I use the HEI electronic tach signal to drive the 68's Aeromotive pump speed controller.

 

I used the Holley dual sync distributor. It has both crank & cam outputs so it makes sequential easy.

That's a Holley filter. The regulator is on the rear of the fuel rail. My fuel system is a rock valley stainless tank with in-tank walbro pump. Stock hardline to that filter. I added a 3/8" hardline return back to the tank.

 

I agree with everything said here.....
I would not even install the EFI if you are not going to use the Timing control......

Jebby

 

Timing control as meaning being able to control the timing and put your own settings verses pre set programs like some of the other efi set ups .

 

I got the proflow 4, when I had a question of concern, I called summit, waited no more than 2 min and talked to pete, (he's the proflow guy to goto) he had me goto my car, start it warm it up and made some changes for the better... there is also the proflow forum and a Facebook group for proflow....sequential over tbi, plus bluetooth..

 

Some of us are just partial to the old mechanical ones with the bouncing needle = I'm one of them. other comments noted as I have an old TPIS mini ram that I would like to get installed on a spare motor I have.

 

I've got a few different cars that I've installed EFI on at various times.

The first is a 66 Mustang with a 289, for it I used FITech and their command center canister, the command center gave me some issues at first, but it's been so long that I don't remember exactly what they were. I do believe there were several other folks having issues with these as well, as this was a one of their new products at the time. Once everything was sorted, the unit has worked fine (over 5 years).
The second is a 72 Challenger with a 340, for it I used the Sniper with inline pump. No issues initially, however, I had to mount the pump right next to the muffler and eventually the pump started sounding weak (I believe due to heat). I then went with a drop in pump/tank from Tanks, Inc. This also alleviated some concerns I had over my return line, as the original style tank used an oddball type vent system. It has ran fine since (around 4 years).
The third is a 72 Corvette with a 350. Again I went with the Sniper, but had some initial issues on this one. Fuel leak around the base of the throttle body onto the intake, had to send it back to Holley for repairs (reported as a ripped o-ring), took around 6 weeks to get it back from repairs. I'm currently having an issue with the car dying after about 30 minutes of drive time, but I don't think it's related to the EFI, though I don't know what is causing it. You'll be driving and it's just like you turned off all of a sudden. New ignition switch didn't help, coil checked good (both cold and hot), but I'm putting another in anyway to be sure. If they doesn't fix it, I'll swap the distributor again.

Easy to find a HEI distributor with mechanical tach output. If my problems end up being due to the distributor then I would say I'm not a good source of info on that, so will so no more.

I don't see it being mentioned as much anymore as I think most manufacturers are now more clear in their instructions and people are aware, but any unit requires a clean 12v source through both start & run. I believe it's easy enough to find a source on the Corvette, but wasn't easy on the Challenger, so I used a timing circuit relay to provide signal to the EFI. They are easier to set-up than they used to be (use an app now, whereas you previously had to use a trigger wire on a 12v source to select the program), can be installed in an easily accessible area of your choosing (so don't have to crawl under the dash), a lot of programming options, and they seem to use quality components. I get them off amazon, the company is called Timers Shop.