legrand88

Have '66 small block and live in Colorado. A 4 hour drive can take me from 5,000' to 10,500' in elevation. The carb can't keep up with the need to change air/fuel mixtures . Stopping very 1/2 hour to re-jet the carb is not the answer. My MPG is a joke. Considering the EFI conversion route. Does anybody have experience with aftermarket EFI conversion packages. Are there reasonably priced options? Would rather consider packages that don't require the return line/replace the gas tank step. Thx, in advance, for the feedback - Brian

cv67

the holley sniper system seems to get real good reviews, simple install self tuning etc can see your issue with elevation.
Think most efis youll need to do a fuel system of some type. In your case id say its worth it you almost have to. Sure will run better
Some of the other systems are good but you may need a laptop to screw with tuning. Some like it some dont

MikeM

.........and I normally am not in favor of making this change but in your case....................

mrtexas

Google FITech 400hp $800, an electronic "carburetor." You would have to purchase a plug for the FI return line from FITech. I have one on a Ford 302 hot rod works fine. I installed an in tank fuel pump and return line. This unit has the computer built in so not a lot of wires to route. You have to install an O2 sensor in the exhaust pipe. To avoid a return line from the engine bay you can use an LS Fuel Filter Regulator($75). You would have a high pressure fuel pump routed to the fuel filter and a return line to the tank from the regulator which you could locate close to the tank. Total installed cost around $1000. I would avoid the FITech fuel sump tank as I have heard a lot of bad press about it. The tank is a surge tank to avoid a return line. If you can take out the gas tank there are kits(TankInc) to add an in-tank fuel pump very easily.

warrenmj

What carb do you currently have? I live in Colorado Springs at 6200 feet and usually stay within 5-9000 feet, but have gone up to 12,000 on my original Holley. It definitely struggled at the higher elevations. I put on a QuickFuel a couple years ago and have it jetted and tuned for 6000' and it runs great, but I have yet to take it over about 8000'. I wanted to drive it to the top of Pikes Peak (14,415') this summer but time got away from me so I will do that next year.

MikeM

............or you could skip the FI and just move back to civilization.

warrenmj

No better place to live than Colorado

SI67

I am contemplating making a similar change on my '67 327/300. Am I correct in thinking that if OP and I stay with stock cast iron manifold (same as what OP's car was built with) that plugging the hot slot is going to be a very important thing to do? And would blocking the intake's exhaust gas crossover passages (using the Fuelie version of the gaskets) along with wiring the heat riser valve open be necessary--or strongly advisable?

All the more reason to consider going to a Performer manifold along with the EFI, I suppose. Does a Performer have the crossover passages, too?

GTOguy

My sentiments are the same as Mike M's. I prefer a well tuned carb on a vintage car, and I know that some of the aftermarket FI systems are a bit wanting in quality control. That said, with the OP's wide range of altitudes encountered in his normal driving routine, an FI system with a good barometric pressure sensing system and a feedback 02 sensor would pretty much solve all of his issues and let him enjoy his classic car. I've driven my old carbureted 4x4 high up in the Sierras and the Rockies, and it performed terribly in comparison to my newer fuel injected 4x4 of the same make. With the fuel injection, there was no degradation in performance at any altitude. No fun chugging up a steep trail at high altitude puking black smoke and running at 50% power!

wmf62

my EFI handled sea level to 11,000 ft with no problems or no retuning from initial set up; I reckon the A/F ratio handled it all

Bill

ghostrider20

Wasn’t there a “dial a jet” metering block sold at one time? Did it Work? Never ran one, but the idea seemed neat.

63split63

You may want to ask if anyone has added FI to a C2 . A stock low profile air cleaner base may not sit down on the throttle body .

mrtexas

I used to have a throttle body on my 63. I've removed it to sell the car. Mine came from Affordable FI. It is based on stock GM throttle body FI.

LB66383

I've been considering an FI conversion as well. One of the concerns I've seen expressed here is companies going out of business or stopping support of their system. For that reason, I've been considering the Edelbrock system. They've been around for decades and are just around the corner from me. They have a fuel pump/tank system that goes in the engine compartment and is fed by the stock fuel pump. However, I got the measurements for that box and made a mock-up, but there was no room in the engine compartment to install it, according to my reckoning. The system would therefore require a higher-pressure pump mounted somewhere with a return line to the tank.

wmf62

....and that is the problem with my ACCEL EFI system, it's an orphan... so far it has been reliable for many years but if something happens to it i'm not sure what I will do... go to another EFI system or back to the Rochester FI.

I must be an orphan magnet, my Keisler SS700 is also an orphan....

Bill

woodsdesign

I had the Accel system and finally decided to go with the Holly Hp FI
It is a great set up. My car runs like modern FI.
I also had an external pump and converted to an in tank unit. It is much better. I had a lot of trouble with the external fuel pump making a lot of noise.

Crunch527

I did one of these throttle body refi systems on my 73 383 when I was in Colorado Springs. Powerjection II...Ran like ****...paid a bunch of money...wasted a ton of time...

I don't think these throttle body units are a "pure enough" efi system to fully address the depth and breadth tuning required with high elevation and changing elevation driving.

There will be guys on this forum that will come out and say, "my XXXX system is awesome"...and that may be true, however, if they are at sea level all the time, their operating environment isn't anything like your operating environment. Stick with the guys that are in the high elevation areas and find out what they use. Not all these systems can handle the range of tuning that is required and be able to do it on the fly.

There was a custom shop in C-Springs right by Peterson AFB and the owner had a 65 Mustang fast back and he had the Edelbrock system on it. He drove the car daily and said the Edelbrock system performed well. I never rode in it, just know what he said. I thought I could save a few bucks and went with the powerjection unit...I also didn't want to swap my intake cause it would void my warranty...what a friggin mess.

4 Speed Dave

This isn't on a vette however is very applicable. I run a Holley Sniper system on my 1970 K series 4x4 truck and have approx 3000 miles on it when it was feeding a GM 350 crate engine the truck came with and about 300 miles in the last 2 weeks on a 406 that I just finished building for it in front of a 700r4 trans. The hardest part is plumbing the return line to the tank. Do not get one of those fuel command center pressure tanks that are mounted in the engine bay. That is the biggest POS thing I have ever seen, all just to avoid plumbing a real fuel return line. Back to the Sniper system. It is a basic throttle body system that also has the ability to control the timing. I am waiting on the dual sync dist as it has been backordered so at this time I am not using the timing controls.

My review of the Sniper is this: There is a good balance of user adjustments and a fairly simple touch screen and self learning parameters to get the engine to run quite well. You don't need a laptop which is a plus for some people. There are no heat soak hard cold or hot starts. The throttle response is like a modern car. AFR (air fuel ratio) is very stable and where you want it to be given your set parameters. Adjustments can be made on with the truck running on the fly with the touch screen. The Sniper system should not even be mentioned in the same sentence as the very old Projection System the two setups are only similar in that they are throttle body injection, the controls are worlds apart.

Other misc items: Before I picked the Holley Sniper system I read about the others out there. Holley had the best after sale reviews and outside vendors that supported their product. FITech had the worst after sale and tech help from what I saw people write. Remember just because it is cheap doesn't mean it is good. Yes the Holley and other systems are more than FItech, there is a reason for this.

The bottom line is that the future is upon us, there are some of us that will embrace new technology and others that will not and will be left behind in the dark. It is the same people that drive EFI everyday in their daily drivers however somehow can't understand that these new retro fit systems can work very well in old iron or fiberglass. I can make 3 whole sale AFR changes before you can even start to remove a screw to drain the gas out of the fuel bowl.

warrenmj

That shop would be Elite Auto and they have done work on my '66 L79, including installation of my Tremec 5 Spd. I highly recommend them.

Crunch527

Yep, that's the place...

legrand88 - call up Elite Auto in CSprings and chat them up about your situation. They will have first hand knowledge of which systems to consider.