Stock 454 carb replacement...use quadrajet or switch to Holley etc
 

I am needing to replace my carb while I have my 454 gen IV motors out. It has a mechanical choke on it and is a regular old quadrajet. Would there be any advantage of me upgrading to a Holley or edelbrock model? If not I have seen some great companies that recast these things and make shiny quadrajet replacements. Also what about adding an electric choke with the new one? Any issues there? Where would one wire in the power?

Whats wrong with your carb? The quadrajets work nice on stock engines, esp a 330.

Electric choke can be wired to the 12v purple wire in your harness. Key on 12V. Key off no voltage.

It's 24 years old. I was just cleaning up the motor and replaced everything with billet parts etc and the carb is junk. I looked a sending it off for a full rebuild and paint and the cost was like $70 different from buying a brand new quadrajet with an electric choke. I was also thinking if a ever decide to do some minor upgrades like exhaust and intake and cam I want to make sure I have plenty of carb to feed that.

Got ya. Well than you can always jazz it up with a pair of these

fixx
 

if it were me i would get new edelbrock airgap intakes and holley 750 annular booster carberators..i would hook a relay to the 12 v purple wire instead of directly to the coil for the choke..you dont need any interferance their,,robbing voltage from the coil's 12volt could short the module..me personally,i have never had a choke on any of my marine engines..pump twice crank it over and once she starts i use the sticks to put the rpm's at 1500 or so just like a car's choke would work...once the temps are at 120* i put the sticks back to zero..

What flow CFM are the quadrajets? Also I agree with using the sticks but I would love to have mine start up more like a fuel injected motor. MILD THUDER is that the quick fuel carb? What sets of intakes will it work with? I can get one of these for $199.95
http://www.nationalcarburetors.com/m...jemc/big/1.jpg
I am not sure if anyone has any experience with national carb but the price seems great.

The quadrajets came in 750CFM for small blocks, 800CFM big Blocks.

Personally, I like the quadrajet. They are/were a very advanced carburetor, and work well. You can get them reman with the divorced choke setup. I don't see why a quadrajet couldn't support 450HP.

You may find a tiny bit of a gain swapping to another carb, but bear in mind the Qjet is one of the most trouble free carbs ever built. As far as starting like fuel injection think about that one! Our engines can sit for weeks, all the time its oil film is draining away. IMO instant start is the last thing you want, I have quite few $$$ in my SB stroker no way do I want instant start.

Phil

Thanks guys loooks like I may just be ordering the above carb with an electric choke option. Can anyone tell me where abouts I will find the purple wire stubbed? I assume since it is part of the engine harness it will have power already supplied to it? Or might be tied into a empty fuse behind the dash?

The purple wire will be in your engine harness, that goes to the coil. Mrfixxall makes a valid point about running it off the wire that powers the coil. Merc did it that way on the 600sc and 800sc though. Seemed to work fine. Wiring it on a relay would be better though.

changing jets on a holly is easier on the quadrejet. if your going to some cam work or exhaust work

Not entirely. A lot can be accomplished with metering rods and hanger. Swapping them is a piece of cake.

I have a Gen V 330, my choke wire is purple with a yellow tracer on it if I recall. Not sure how different the harness between a MKIV and GenV is. I would imagine the boat had carbs with electric chokes on it originally, maybe a previous owner clipped the choke wire back at the harness...

You don't need a choke. A common mod on Holley type carbs is to mill off the choke housing for better airflow. This is from my '82 Mustang. The boat has EFI. ( I see a rotten vacuum port plug...)
http://i763.photobucket.com/albums/x...ps2c452d12.jpg

Pussed out and went with the old style choke. So basically just a $200 fully replated rebuilt carb.

FWIW, I helped a friend with his Nove that ran in a stock class so he had to run a Quadrajet, we were making over 500hp with no problem. the one issue the quad has is that the fuel resevoir area is small so they are not good if you are making lots of power and a lot of rpm for long times unless you upgrade the fuel system. we ran a bypass regulator to feed all the fuel to the carb and after that it never starved up to 7200rpm. if you know how to work on them the quad is one of the most adjustable and durable carbs out there.

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