Q-Jet setup for a Chevrolet Performance 454 HO

[Kjetil]

Hi Cliff and all!

First of all: the rebuild I did for my Buick 430 using your book and parts was a great success! The learning value was tremendous, and I really feel that I understand the Q-jet principles now.

I'm planning to step things up with a Chevrolet Performance 454 crate engine. The specs are:

-425 HP @ 5250 RPM
-500 ft/lbs TQ @ 3250 RPM
-8.75:1 Compression Ratio
-Hydraulic Roller Cam (Lift .510" Int/.540" Exh, Duration @ .050" 211° Int/230° Exh)
-Cast Iron Rectangular Port 118cc Cylinder Heads (2.19" Int/1.88" Exh valves)
-1.7:1 Rocker Arms

The transmission will be a TH-400, and the rear end has a 2.73 gear ratio. The car is a 1975 Monte Carlo.

I have a Quadrajet I bought years ago with a project like this in mind. The number is 17058213. Using your casting number guide I decode it as:

- year of 1978
- federal
- Chevrolet
- manual trans

However, there is a stamp on the carb that says: "MFD by Carter Carburetor for GMC".

I've disassembled it and got a bad start with broken bolts in all the shafts. Will pull the idle tubes this weekend.

So my questions are:

1. Is the particular carburetor a good base for further modification?

2. Could you recommend a Q-jet recipe for the application? Would for instance recipe 1 or 2  in your book be sufficient?
I'll order parts accordingly.

Regards

Kjetil

[Cliff Ruggles]

Those are nice units, but divorced choke.  If you require a choke for the project, I would get a 1976 or later Chevy q-jet that had the hot-air choke, as it easily converts to electric......Cliff

[Kjetil]

Sounds good, I can live without the choke.

Maybe I should send you an e-mail regarding a "recipe"?

Kjetil