Quadrajet Mystery and questions

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.

grummy

Junior Member
Joined
Aug 21, 2024
Posts
13
Reaction score
30
Location
Midwest
First Name
Chris
Truck Year
1983
Truck Model
C1500
Engine Size
305
In August, I picked up a 1983 GMC C1500 w/ 305 (H-ESC), 700r4 and 273:1 ratio. Story was it had been parked in a shed for many years with little use by second owner who passed prior to his 90th birthday. Oil change sticker indicated that it moved 400 miles since early 2019, and was told by family they used it for a dump run now and then. The truck appeared to be an unmolested original. After a few months of work, she goes down the road really well. Real happy. Under the hood, it appears to have every vacuum line intact, Air cleaner tubes, etc correct, ESC is working, 700r4 shifts proper. I find that the original vacuum routing label is missing, because it did have radiator support replaced due to a light front right crash (Reight Fender, inner Fender obviously replaced). No big deal.

I thought I would order a carb kit to have ready for spring. Carb # is 17056202. Surprise to me!, looks like carb has been replaced with a 1976 era carb. Unfortunately, I can not find that exact carb number, though I find ones close.... 6208 for a 1976 Buick Lesabre (I think). Not sure I should even order a kit just yet. I have no indication that it originally had an "electronic controlled" carb as there are no spare plugs/wires anywhere. Rock Auto shows the replacement as an M4ME.

Well, the QUESTION really is >>> if I were to take this to a Carb rebuild fellow, what should I tell him to get it to be rebuilt with proper jetting for this 1983? I've done a few 60 mile loops with the truck so far and seem to get about 13mpg max. No cruise, just a steady pedal. I realize the EPA figure claiming 20mpg for 1983 is wacko, but I'm thinking with the overdrive and 273 rear, it could do better than 13... perhaps 16 should be possible the way I drive it.

OR, should I attempt to find an M4ME for any specific reason ? Thanks in advance. I've often swapped Quads around just to make stuff run, but for the first time in my life, I'd like to do a quad right, or as right as possible.
 

Snoots

Full Access Member
Joined
Jan 23, 2013
Posts
8,850
Reaction score
18,581
Location
Georgia
First Name
Roger
Truck Year
1973
Truck Model
Jimmy Sierra
Engine Size
350 w/203

grummy

Junior Member
Joined
Aug 21, 2024
Posts
13
Reaction score
30
Location
Midwest
First Name
Chris
Truck Year
1983
Truck Model
C1500
Engine Size
305
Wow, thanks fella's. That Cliffs forum looks like I can learn a lot there. And, the PDF will be tonights reading.

I went out in the garage and found a carb off of my old '81 Chevy P30 # 17080204. This looks to be closer at least in age, but it was on 350/auto truck. I do know it was original to that truck and I got decent mileage with it even though it was a 14' Step Van.

I'm thinking this might be a good donor. I think Cliff's might be able to ID the exact jets, rods and hangers the original truck had. GREAT INFO ! Thanks Again !
 

77Dmax

Full Access Member
Joined
Nov 10, 2024
Posts
69
Reaction score
131
Location
vt
First Name
Joe
Truck Year
1977
Truck Model
c20
Engine Size
6.6
The buick carb will have a straight inlet fuel line. I thought the thermostat housing on a SBC made it unable to run a straight inlet carb.. i seem to remember trying this years ago and it didn't work.
 

Turbo4whl

Supporting Member
Supporting Member
Joined
Oct 30, 2019
Posts
3,150
Reaction score
7,307
Location
Downingtown, PA
First Name
Wayne
Truck Year
1974
Truck Model
Jimmy
Engine Size
350
I find that the original vacuum routing label is missing, because it did have radiator support replaced due to a light front right crash
You must be registered for see images attach
 

grummy

Junior Member
Joined
Aug 21, 2024
Posts
13
Reaction score
30
Location
Midwest
First Name
Chris
Truck Year
1983
Truck Model
C1500
Engine Size
305
The buick carb will have a straight inlet fuel line.
Yep, your right. Carb on it now (17056202) does feed from the left side, so it is Chevy. Another site now indicates Camaro and Corvette.

I have been searching now for what jets/rods may have been in the '83 truck from the factory. No luck yet with something absolute.

Thanks ! Current carb pic is because we all like pic's !
 

Attachments

  • 1a20240923_154045.jpg
    1a20240923_154045.jpg
    186.4 KB · Views: 4

Forum statistics

Threads
44,367
Posts
955,427
Members
36,631
Latest member
Tonysmobile
Top