305 Quadrajet to EFI

[LukeZ]

Hey guys,

Ive been thinking about switching to EFI on my 305 for better fuel management (mostly I want better mileage and throttle response. It's just a daily). I have the stock 4 Barrel quadrajet and my intake manifold is an Eddy Performer Air Gap.

Two big questions: first, are there aftermarket EFI systems that bolt up in place of a spread bore carb like the Qjet? Id like to keep the intake manifold. Second, how much fabrication has to be done to the fuel system? Is it just bolt-in type stuff? I understand there's a whole computer aspect to it also, but that there are also self-learning systems out there.

Thanks for any info

 

[565bbchevy]

First what is your budget for the conversion? Not only do you need the EFI system which start at $800 you will need the fuel system to support it.
I do believe all of these systems that replace a carb are designed for square bore manifolds.

 

[86LK]

https://fitechefi.com/products/30003/

I've heard good things about this system from other forums I frequent

from page 1 of the instruction manual
"About your FiTech Go EFI System
The Fitech Go EFI System will bolt directly to any 4-BBL intake manifold. To fit on a spread bore 4-BBL manifold will require an inexpensive adapater plate to avoid leaks. Note that the FiTech throttle body will bolt directly to a spread bore 4-BBL manifold but may leak without the adapter plate. Suitable adapter plates are available from several suppliers such as Summit Racing (SUM-G1420)."

https://www.summitracing.com/parts/sum-g1420 ($7)

 

[LukeZ]

First what is your budget for the conversion? Not only do you need the EFI system which start at $800 you will need the fuel system to support it.
I do believe all of these systems that replace a carb are designed for square bore manifolds.

It's not a high dollar race car or show car or anything, so as far as quality goes it doesn't have to be top of the line. I think I could do 1000 and be okay with it. And I think you're correct, because I was looking online the other day and every single system I found was a square bore replacement.

 

[LukeZ]

https://fitechefi.com/products/30003/

I've heard good things about this system from other forums I frequent

from page 1 of the instruction manual
"About your FiTech Go EFI System
The Fitech Go EFI System will bolt directly to any 4-BBL intake manifold. To fit on a spread bore 4-BBL manifold will require an inexpensive adapater plate to avoid leaks. Note that the FiTech throttle body will bolt directly to a spread bore 4-BBL manifold but may leak without the adapter plate. Suitable adapter plates are available from several suppliers such as Summit Racing (SUM-G1420)."

https://www.summitracing.com/parts/sum-g1420 ($7)

I like the look of that one, thanks for linking it. The price is good and it looks like it's meant for a daily driver.

A question about EFI kits in general: do they have linkage that connects to the gas pedal like a regular carb? Or do you usually have to convert your pedal setup to something electronic?

 

[N3M3S1S]

I like the look of that one, thanks for linking it. The price is good and it looks like it's meant for a daily driver.

A question about EFI kits in general: do they have linkage that connects to the gas pedal like a regular carb? Or do you usually have to convert your pedal setup to something electronic?

I helped a friend install the FiTech onto his 85 Trans Am. It pretty much bolts right into place where the old one did and you slide the linkage on the same way. There's really only a few wires it needs hooked up if you've got HEI. It was simple. I'd recommend going with an in-tank fuel pump like one meant for a Grand National or the FI 4.3 Monte because the external pump he bought with the kit is annoyingly loud. On a daily I wouldn't be able to deal with it.

Edit: Lol I just noticed it said you're from Delaware too. Small world!

 

[LukeZ]

I helped a friend install the FiTech onto his 85 Trans Am. It pretty much bolts right into place where the old one did and you slide the linkage on the same way. There's really only a few wires it needs hooked up if you've got HEI. It was simple. I'd recommend going with an in-tank fuel pump like one meant for a Grand National or the FI 4.3 Monte because the external pump he bought with the kit is annoyingly loud. On a daily I wouldn't be able to deal with it.

Edit: Lol I just noticed it said you're from Delaware too. Small world!

Oh okay awesome, that's grea news. The easier the better haha. As far as HEI, I just have the stock Delco Remy distributor on the engine, so I'm not sure if that means HEI or not. I assume yes?

Was the external pump your friend had just and electric one or something? Yea, I may just go with an in tank one if that's less annoying.

And yea man small world! I'm actually from Smyrna but I go to school at UD so I'm in Newark most of the year!

 

[Wraith]

You are going to spend more money as you have an El Camino and have to go external fuel pump or with the universal in tank conversion, the Monte/Regal stuff won't work with your gas tank. I'd say stick with a well built, non-computer, quadrajet for a normal daily that runs low miles. Fuel injection doesn't always return better mileage, it will require more work. What rear gears do you currently have? That may return better mileage if you are trying to drag it around with a 2.29 gear.

 

[pagrunt]

Look into 4.3 Elky's for a possible source for the fuel tank/pump.

 

[LukeZ]

You are going to spend more money as you have an El Camino and have to go external fuel pump or with the universal in tank conversion, the Monte/Regal stuff won't work with your gas tank. I'd say stick with a well built, non-computer, quadrajet for a normal daily that runs low miles. Fuel injection doesn't always return better mileage, it will require more work. What rear gears do you currently have? That may return better mileage if you are trying to drag it around with a 2.29 gear.

I'll have to price it all out to see if the work is worth the gas savings. I have long commutes so that's why I think it'll pay off, but we'll see. It has 2.56s btw. Thanks for the heads up about the pump