Quadrajet

[ejames]

Quadrajet 4 Barrel Carburetor
Manufacture: Rochester
Type: R4-4MC (choke on passenger side)

GM Motorhome 73-74 (455)
7043254 – Federal

GM Motorhome 75-77 (455)
7045254 – Federal – Rebuild Kits: NAPA Echlin 2-5561A
7045554 – California

GM Motorhome 77 (403)
17057254 – Federal – Rebuild Kit: Delco 17076031
17057559 – California – Rebuild Kit: Delco 17076031

GM Motorhome 78 (403)
17058559 – Federal – Rebuild Kit: Delco 17076031
17058254 – California – Rebuild Kit: Delco 17076031

Tornado (455)
Part Number: 7043252
Note: identical to the 7043254 except for the jets, rods and power valve spring [link]

Springfield Ignition (Dick Paterson) rebuilds the GMC carburetor.

Quadrajet Power sells rebuild kits, you just need to provide you carburetor model number.

 

[pvfjr]

Good info, I'll have to try to identify the remanufactured unit I found in the back of our RV. I'm curious if it's the right one.

 

[ejames]

Good info, I'll have to try to identify the remanufactured unit I found in the back of our RV. I'm curious if it's the right one.

What does your air intake look for the one that's in there? Is the hatch raised? A friend has an aftermarket carter in his and the bumped the dog house up and just tossed a round air cleaner on it. So once the engine heats up it's just drawing in hot air, performance is crap.

 

[pvfjr]

What does your air intake look for the one that's in there? Is the hatch raised? A friend has an aftermarket carter in his and the bumped the dog house up and just tossed a round air cleaner on it. So once the engine heats up it's just drawing in hot air, performance is crap.

The current setup is awful, much like you describe. There's a spreadbore to square bore adapter, and 3/4 to 1" thick phenolic spacer, an edelbrock performer, and some random round air cleaner. The engine cover is framed with 2x4s framed up on edge along with heavy plywood--it sticks way up and weighs a ton. It also has no handles, or no hardware for attaching it down (I have to stack heavy stuff on it to keep it in place at high speeds).

I pretty much want to change all of it. I'd like to run some sort of intake tube from a newer model toward the front. I may even play around with some thermocouples and dataloggers to improve the intake air temperatures.

 

[Tony Hibl]

Quadrajet 4 Barrel Carburetor
Manufacture: Rochester
Type: R4-4MC (choke on passenger side)

GM Motorhome 73-74 (455)
7043254 – Federal

GM Motorhome 75-77 (455)
7045254 – Federal – Rebuild Kits: NAPA Echlin 2-5561A
7045554 – California

GM Motorhome 77 (403)
17057254 – Federal – Rebuild Kit: Delco 17076031
17057559 – California – Rebuild Kit: Delco 17076031

GM Motorhome 78 (403)
17058559 – Federal – Rebuild Kit: Delco 17076031
17058254 – California – Rebuild Kit: Delco 17076031

Tornado (455)
Part Number: 7043252
Note: identical to the 7043254 except for the jets, rods and power valve spring [link]

Springfield Ignition (Dick Paterson) rebuilds the GMC carburetor.

Quadrajet Power sells rebuild kits, you just need to provide you carburetor model number.

I believe there is a typo in your post. The carburetor part numbers for the ‘78 GMC Motorhome appear to be reversed. I believe the 17058254 is the Federal carburetor, not the California carburetor. And, the 17058559 is the California carburetor, not the Federal carburetor.