Which carb to buy?

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Mudgunner

Junior Member
Joined
Jul 30, 2020
Posts
3
Reaction score
6
Location
Gagetown, New Brunswick
First Name
Mark
Truck Year
1981
Truck Model
GMC K1500
Engine Size
350
I’m starting my restoration of my 1981 GMC High Sierra 4x4 with original 350 4 bolt main engine. I’m going to replace the carburetor but not not sure which to go with. I’m thinking Edelbrock but not sure which model? My truck will not be lifted or used off road. I’ll be driving it on country roads and some highway. I’m not looking to drag race it, I just want a great performing engine. Any recommendations?
 

wanderinthru

Full Access Member
Joined
Jul 23, 2020
Posts
1,170
Reaction score
2,046
Location
Mid Point Route 66
First Name
Shakey
Truck Year
81, 70, 75, 84, 89
Truck Model
K 10, C 30, K 20
Engine Size
350
I personally get along with the elderbrock, think mine are 1406. Though I'm itching to try one of their TSV 2 or 3's might look into them. If you go elderbrock, go ahead and buy a tuning kit for the carb. Plenty of stuff on you tube to see how to tune one, pretty easy.
 

gotyourgoat

Full Access Member
Joined
Mar 27, 2014
Posts
2,117
Reaction score
3,417
Location
NRV Virginia
First Name
gotyourgoat
Truck Year
1984
Truck Model
c10
Engine Size
smokin' 305
Quadrajet would be my choice. I see you are from a pretty cold climate though, have you thought about going with an efi system?
 

CrazyArk

Member
Joined
Feb 28, 2020
Posts
38
Reaction score
59
Location
Bungatoolies AZ
First Name
Ark
Truck Year
1986
Truck Model
C2500 High Sierra
Engine Size
355 (0.030+)
...Everyone has their preferred carb, and it can vary heavily from person to person. Edelbrock has by far the easiest to maintain. The fact I, a complete newbie to rebuilding carbs could strip mine down, clean it, and reassemble it says a lot. Quadrajets, depending on how fancy you wanna go do have a nice factor, smaller primary, larger secondary, can help you a bit on fuel. I wont deny, the truck I have driven WITH a Quadrajet has given me a very healthy appreciation for the monstrosity they are to strip down and rebuild.

Personally, I like the 1405. But I am a sucker for a preference for manual choke. (plus it came free with the truck.) The 1406 is the same carb overall, but it is the electric choke version. I see no reason to go over a 600cfm Edelbrock with what I have learned so far. I havent learned nearly enough with their newer carb versions, Would need others to chime in on their efficiency rates.
 

Rusty Nail

Full Access Member
Joined
Jan 29, 2015
Posts
9,735
Reaction score
9,532
Location
the other side of the internet
First Name
Rusty
Truck Year
1977
Truck Model
C20
Engine Size
350sbc
You said restore
I say rebuild the correct Quadrajet.
It's a Faaaaaaaaar superior carb to an edelbrock / Carter piece of ****.

Or at least buy a Holley. SA670. .Best to rebuild your OE carb though. You won't find anything that will perform better. Imo.
Edelbrock carbs ******* suck.
 
Last edited:

Octane

Full Access Member
Joined
Dec 31, 2019
Posts
1,990
Reaction score
3,549
Location
Atlanta
First Name
Eddie
Truck Year
1977
Truck Model
K10
Engine Size
350
I have luck with Rochesters if it's a decent core.A bad one is a very bad experience.Edelbrock in early years were carter.Later on lots of them were weber.I only had one and it did well enough on a 350 I built with a slightly over stock cam.But I've heard the hate on them but a little adjusting is all I've ever had to do.But I have to say I've had a few Rochesters and had to rebuild every single one.But I always liked the way they ran on a daily driver
 

75gmck25

Full Access Member
Joined
Oct 13, 2016
Posts
2,018
Reaction score
1,811
Location
Northern Virginia
First Name
Bruce
Truck Year
1975
Truck Model
K25 Camper Special TH350 NP203
Engine Size
5.7
I am currently using a Quadrajet and it now works well, but the truth is that getting a 40+ year old carb to work properly with a modified engine was not that simple. Quadrajets are infinitely tunable, but that is also why they are complicated to get properly adjusted. And when you rebuild one you are trying to fix the mistakes of past owners, which is also frustrating.

For a new carburetor I have found the Edelbrock AVS2 has gotten really good reviews, and it has several improvements over the old 1406. Almost every review talks about its crisp throttle response.

Bruce
 

wanderinthru

Full Access Member
Joined
Jul 23, 2020
Posts
1,170
Reaction score
2,046
Location
Mid Point Route 66
First Name
Shakey
Truck Year
81, 70, 75, 84, 89
Truck Model
K 10, C 30, K 20
Engine Size
350
I am currently using a Quadrajet and it now works well, but the truth is that getting a 40+ year old carb to work properly with a modified engine was not that simple. Quadrajets are infinitely tunable, but that is also why they are complicated to get properly adjusted. And when you rebuild one you are trying to fix the mistakes of past owners, which is also frustrating.

For a new carburetor I have found the Edelbrock AVS2 has gotten really good reviews, and it has several improvements over the old 1406. Almost every review talks about its crisp throttle response.

Bruce

Same thing I've heard. Way I understand it is instead of it letting the fuel in through a single tube, it has a ring with a bunch of little holes. supposed to help atomize the gas which makes alot of sense. That what your understanding Bruce?
 

AuroraGirl

Full Access Member
Joined
Sep 8, 2019
Posts
9,121
Reaction score
6,038
Location
Northern Wisconsin
First Name
Taylor
Truck Year
1978, 1980
Truck Model
K10, K25
Engine Size
400(?), 350
...Everyone has their preferred carb, and it can vary heavily from person to person. Edelbrock has by far the easiest to maintain. The fact I, a complete newbie to rebuilding carbs could strip mine down, clean it, and reassemble it says a lot. Quadrajets, depending on how fancy you wanna go do have a nice factor, smaller primary, larger secondary, can help you a bit on fuel. I wont deny, the truck I have driven WITH a Quadrajet has given me a very healthy appreciation for the monstrosity they are to strip down and rebuild.

Personally, I like the 1405. But I am a sucker for a preference for manual choke. (plus it came free with the truck.) The 1406 is the same carb overall, but it is the electric choke version. I see no reason to go over a 600cfm Edelbrock with what I have learned so far. I havent learned nearly enough with their newer carb versions, Would need others to chime in on their efficiency rates.
More CFM is unfortunately equated with more power when there is a cut off where you need to do internal changes to your engine to need more than 600 generally. Race cars putting out 400hp or so with 107 or so octane gas be using 500cfm 2 barrels... its about how an engine is built and much more complex things than i am qualified to list.

But once you reach the higher CFM point, definitely a good point.

Same thing I've heard. Way I understand it is instead of it letting the fuel in through a single tube, it has a ring with a bunch of little holes. supposed to help atomize the gas which makes alot of sense. That what your understanding Bruce?
Power blast or something is a company that claims to make bolt on parts that do just that for 1406. i might try it for 40 bucks once my truck runs a consistent, good way that i can use as a before/after statement.
 

AZ-520

Junior Member
Joined
Jun 8, 2019
Posts
9
Reaction score
8
Location
85711
First Name
Eric
Truck Year
1983
Truck Model
c-10 2wd
Engine Size
5.9l
Edelbrocks are great and easy to tune regardless of what dude said above, I like all carbs and they are all pretty good. You need to take the time to tune it properly. Do yourself a favor and get and AFR gauge so you can easily dial in any fuel system you go with.
 

Ricko1966

Full Access Member
Joined
Apr 11, 2017
Posts
3,943
Reaction score
5,692
Location
kansas
First Name
Rick
Truck Year
1975
Truck Model
c20
Engine Size
350
The quadrajet ran for decades, trouble free on new GM cars Vettes to farm trucks.A good quadrajet requires practically zero attention, if they were troublesome or inferior GM wouldn't have used them for so long.Next best thing to TBI IMHO. And I've had quadrajets, edelbrocks,Holley, webers. I've said it before and will say it again when people say they put x brand carb on and their truck ran so much better, they are comparing a 45 year old quadrajet that needs rebuilt to a brand new brand x. And anything other than stock is not restored, it's modified.
 

Hugeroost

Junior Member
Joined
Sep 9, 2019
Posts
21
Reaction score
10
Location
Texas
First Name
Kyle
Truck Year
1979
Truck Model
c10
Engine Size
350
Hands down HOLLEY, or you will be fiddling with it forever!!:cheers:
Agreed, its damm near impossible to rebuild one of those things and it run right, of course there's 30 guys on here that did it. My opinion of a quadrojet, and Ricko touched on it, they are fine when you buy new truck or car, but once it needs to be gone thru its best to throw it in the garbage and buy edel/holley. OP needs aluminum intake, headers, full duel exhaust, and a holley/edelbrock and he'll never have to touch it again. Also a stock 350 or even a cammed one w heads only needs 600cfm max. My last one, since I had em on the shelf, I went from 750 to 650 to a 550 and the latter found the sweet spot, it had heads and a cam as well....Roost
 

75gmck25

Full Access Member
Joined
Oct 13, 2016
Posts
2,018
Reaction score
1,811
Location
Northern Virginia
First Name
Bruce
Truck Year
1975
Truck Model
K25 Camper Special TH350 NP203
Engine Size
5.7
As I mentioned, I'm using a Quadrajet and it currently works well. However, just to give you an idea of the configuration/tuning choices you have with a Quadrajet, these are some of the items I recorded for my carburetor. If I made a significant change in cam, heads or other parts I might have to go back through these settings to figure out what needed to be "tweaked." It is not a simple process.

Quadrajet 17080213 Q243 CPX
Idle tube .038
Idle down channel .055
Upper air bleed – in air horn, .052
Lower air bleed – .0625
Idle air – .110
Mixture screw hole – enlarged to .078
Jets #74
Primary rods - 50C
Secondary rods - DA
Secondary hangar - G
APT - 2 ½ turns out
Idle screws - 3 ¼ turns out
Power piston spring – red
Notched secondary flaps next to accelerating system holes
Secondary air valve ¼ turn tension
Accelerator pump - 2nd hole
Blue seal on accelerator pump
Float at 1/4”
2104 gasket

Base timing 15 BTDC
Mechanical adds 20 degrees by 2000 RPM
Manifold vacuum
15 degree vacuum advance

Bruce
 

Forum statistics

Threads
41,855
Posts
903,581
Members
33,368
Latest member
TheDuke
Top