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Discussion Starter · #1 · (Edited)
I’m trying to decode this quadrajet number the the “Julian” numbers 0486 after the 7044288 are confusing me. Based on the first number this is a 1974 from a Checker or Marine engine. What does the second set of numbers mean? Looking for a replacement for my street/strip 355sbc.

Also, based on the photo from the side would I be able to add an electric choke?
524964
524975
 

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Interesting combo.
1974 carb with the 66-67 secondary lockout. Maybe because it’s a marine carb.
Might be a good carb if your motor is mild.
Electric choke kits are available to fit that divorced choke carb.
After a quality rebuild kit for 80 bucks, electric choke for 60 more, you might be better off with a rebuilt or a different carb.
What’s the specs on your 355?
 

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Interesting combo.
1974 carb with the 66-67 secondary lockout. Maybe because it’s a marine carb.
Might be a good carb if your motor is mild.
Electric choke kits are available to fit that divorced choke carb.
After a quality rebuild kit for 80 bucks, electric choke for 60 more, you might be better off with a rebuilt or a different carb.
What’s the specs on your 355?
I don't know where you're buying your parts ,a quick search shows carb kits for about $20 , a MANUAL choke conversion is about $25 , an electric conversion , I'd go to swap meets/ junkyards , somebody's stash & scrounge parts . But I've always been broke too !
 

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Key word is quality.
Cliff Ruggles kits come with everything to custom calibrate your carb. Not just your cheap kits with new gaskets and a check ball.
Manual choke is tough to do on a divorced choke carb.
Stand alone electric choke replacements for the choke stove are available.
 

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Is this a good performance build platform or should I pass until I find something with electric choke already?
Qjets , IMO , are the best street performance carb ever built . It will take some study to become proficient at dealing with them . Take this for what its worth. , most of the modifications done to carburetors are for naught & may render a carb useless . Factory engineers spent millions perfecting air/ fuel ratios based on how much air the carb is flowing . Other than exercising your abilities at playing with your carb there isnt a lot to be gained by " messing" with it . Best to choose the right size carb for your engine instead !
 

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Key word is quality.
Cliff Ruggles kits come with everything to custom calibrate your carb. Not just your cheap kits with new gaskets and a check ball.
Manual choke is tough to do on a divorced choke carb.
Stand alone electric choke replacements for the choke stove are available.
Bet ruggles buys most of his kit parts the same places everyone else does ..:rolleyes:
 

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Discussion Starter · #9 ·
Interesting combo.
1974 carb with the 66-67 secondary lockout. Maybe because it’s a marine carb.
Might be a good carb if your motor is mild.
Electric choke kits are available to fit that divorced choke carb.
After a quality rebuild kit for 80 bucks, electric choke for 60 more, you might be better off with a rebuilt or a different carb.
What’s the specs on your 355?
Its not real mild.

Vortec heads
RPM Performer intake
XR274H roller
9.8:1 compression
2800 stall
700r4
 

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Leave the quadrajet on the shelf.

I’d go like this Holley.
Easy to tune, adjust etc.

 

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I have a dart small chevy 377 shp build and run aroud 9.8 to 1 compression ratio (4.155 bore x 3.48 stroke) with flat top pistons 2 valve and dart pro 1 200 cc platinum aluminum heads all ported out and gasket matched and worked over very well and run a edelbrock rpm performer air gap intake and a 220/[email protected] 510/510 lift with a 114 lsa and I won't bother with the rest and its in a 96 chevy s10 with a 3000 plus stall convetor and turbo 350 and I can run a 650 double pumper or a 650 vacuum secondary and I get 19 mpg on my build going down the highway at a steady speed of 60 mph at 2800 rpm if I keep it that way and slightly less at 70 mph at 3200 rpm. I also ran a holley 750 HP which is for all out performance and still got the same mileage with proper time and tuning.

Holley carburetors will never do as good as a Qjet for mileage since they have smaller primaries for better fuel atomization and throttle response but for all out performance its my experience and just my two cents that a holley carburetor will outdo a Qjet for overall all around performance any day of the week and that is why most people use them and a Qjet was never meant for all out racing motors which is the reason why they don't get used as much as they were meant more for everyday driver cars and trucks etc.

I would check out holley store on ebay and look under there refurbished carburetors and they have some good deals on the quick fuel slayer 600 vacuum secondary carbs at times for around $250 bucks or so and some of the holley brand 600 vacuum secondary ones can be a little cheaper yet. They also have some 750 carbs for around $300 and are great buys. They are mostly ones people bought and did not have them adjusted right and thought something was wrong with them and they just did not know what they were doing and holley will resell them for a cheaper price since they were installed.

A holley can be made to do decent on fuel mileage if you learn how to tune one and know your way around them. My brother once had a bone stock 305 small block chevy in a 88 chevy caprice and his carb was shot and I replaced it with a holley 600 vacuum secondary which is not the best for mileage compared to a Qjet but with some time and tuning I got it pretty close to almost making the same mileage as his Qjet did when it was working good before it went downhill after getting worn out.

His Qjet had some things so worn out on it at its final years that it would have cost more to fix it then what it was worth so I bought a used holley from ebay and fixed it up for the cheap and it was in good shape still.

Just my experience and from reading on other racers out there that have went both ways with carbs and different brands and styles. I am not saying I am right as its just my opinion as all carburetor designs have there pros and cons when it comes to tuning and there design and ease of making them perform more then what they was made for.
 

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Discussion Starter · #15 ·
I have a dart small chevy 377 shp build and run aroud 9.8 to 1 compression ratio (4.155 bore x 3.48 stroke) with flat top pistons 2 valve and dart pro 1 200 cc platinum aluminum heads all ported out and gasket matched and worked over very well and run a edelbrock rpm performer air gap intake and a 220/[email protected] 510/510 lift with a 114 lsa and I won't bother with the rest and its in a 96 chevy s10 with a 3000 plus stall convetor and turbo 350 and I can run a 650 double pumper or a 650 vacuum secondary and I get 19 mpg on my build going down the highway at a steady speed of 60 mph at 2800 rpm if I keep it that way and slightly less at 70 mph at 3200 rpm. I also ran a holley 750 HP which is for all out performance and still got the same mileage with proper time and tuning.

Holley carburetors will never do as good as a Qjet for mileage since they have smaller primaries for better fuel atomization and throttle response but for all out performance its my experience and just my two cents that a holley carburetor will outdo a Qjet for overall all around performance any day of the week and that is why most people use them and a Qjet was never meant for all out racing motors which is the reason why they don't get used as much as they were meant more for everyday driver cars and trucks etc.

I would check out holley store on ebay and look under there refurbished carburetors and they have some good deals on the quick fuel slayer 600 vacuum secondary carbs at times for around $250 bucks or so and some of the holley brand 600 vacuum secondary ones can be a little cheaper yet. They also have some 750 carbs for around $300 and are great buys. They are mostly ones people bought and did not have them adjusted right and thought something was wrong with them and they just did not know what they were doing and holley will resell them for a cheaper price since they were installed.

A holley can be made to do decent on fuel mileage if you learn how to tune one and know your way around them. My brother once had a bone stock 305 small block chevy in a 88 chevy caprice and his carb was shot and I replaced it with a holley 600 vacuum secondary which is not the best for mileage compared to a Qjet but with some time and tuning I got it pretty close to almost making the same mileage as his Qjet did when it was working good before it went downhill after getting worn out.

His Qjet had some things so worn out on it at its final years that it would have cost more to fix it then what it was worth so I bought a used holley from ebay and fixed it up for the cheap and it was in good shape still.

Just my experience and from reading on other racers out there that have went both ways with carbs and different brands and styles. I am not saying I am right as its just my opinion as all carburetor designs have there pros and cons when it comes to tuning and there design and ease of making them perform more then what they was made for.
Thanks Eric, you actually worked with me extensively last month to tune my Demon idle and my vacuum advance. I have since tore the motor down for high cylinder leakage and obnoxious oil consumption. I am getting some machine work done and will be reinstalling the demon since you helped me get it running wonderfully!
 

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I did not realize it was you as its hard to keep track of everything but sorry about your build and how it went. I have been there before where you just get your build put in and then something decides to go wrong and you have to pull it all the way back out and tear down.

I once had a fresh new build and everything was fine for about three days and then all of a sudden my oil pressure would not stay steady when cruising it would go the drop and then pick back up real fast and turned out to be the pump was hanging up or something as the pump was brand new and checked.

Took it out and installed a different pump and problem solved. Then another time the front one piece gasket which I have never had luck with on the oil pan leaked really bad on the front U channel on the bottom and it was the right thickness of the front part and it was on a brand new oil pan and not a cheapy one.

Had to take the whole engine out just to change the gasket and I then use the four piece and ditched the front and back rubber gaskets and just use gasket maker and then the composite gaskets on the side and had way better luck with that over the years.

Things happen sometimes and I read you had the wrong rings in your build but mistakes can happen its just expensive ones. I once used a pete jackson gear drive and I almost lost my engine because of using one of those things as well. Also had a complete engine brand new built together once again and had to take it out as the stupid world product heads put umbrella seals on a dual spring setup and I did not catch that and it was getting crunched up and down and it allowed a lot of oil get pulled into the intake ports and my valves had so much carbon build up and wet oil on them it was horrible.

The guides were iron and they were fine but the seals were not correct for those heads and I bought them assembled and did not know that you can't use umbrella seals on dual springs and I was still really green back then and have learned quite a lot more since then. I had to get new bronze liners put into my heads so I could get the better valve seals but the type the machine shop put on was not viton ones that most aftermarket heads has and it only worked for a slight time before it started to pull oil through the seals again and I brought my heads back to the shop and the world heads never came with bronze guides and the cost of putting on new seals and them not having bronze guides and the cost of getting them redone as the valves were once again in crusted full of oil deposits and carbon build up I just sold the heads and got a set of different brand heads with all the correct stuff for a dual spring setup and pulled it apart and checked them all over for proper everything as I learned you can't buy assembled heads and think there all right.

Same as new carburetors I always tear them down to check everything over to make sure there is no machining problems or mismatched bleeds or other things. We all make mistakes and learn from them. Good luck on rebuilding your engine and hope it works well this time.
 
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