Hey guys. I am planning on replacing the origonal carb on my 77 and was wondering what i should buy. Any suggestions?

 

100% satisfied with my holley quadrajet replacement. I had my quadrajet rebuilt by an "expert". Problems, problems. Just my experience. Good luck on your choice

 

demon or holley...i like demons better
here is a 600 roady that would prob suit you well

 

When they're dialed in, they can't be beat. Getting them right takes some massaging and not everybody feels competent to do it. Some Holley "experts" are shadetree so they'll take your money then leave you more frustrated than ever.

Rebuilt Quadrajets are fine too - and they respond well to some love.

For plug and play carbs for the street, the Edelbrock is my usual recommendation. Two screws to adjust to the highest manifold vaccum reading then set the idle screw and close the hood.

 

Yes, the Edelbrock is simple and reliable, but performance wise it will be a disappointment. The same with Holley. Don't get me wrong, you can get them to go fast, but if you do, they will drink gas around town. To get tolerable fuel economy, you will loose speed.

Additionally, Holley, while once a name that meant quality, now produces cheap junk and survives on their past glory. Oh, most people will say they have had no problems with their new Holley (75 %), it's that other 25 % you are really going to hate.

Your original carb is a higher quality piece than anything else you can buy. A properly rebuilt Quadrajet is unbeatable. It is the only carb that can be tuned for optimum fuel economy and ultimate wide open throttle performance at the same time. Anyone who says differently does not understand how these carbs work, period. For a street car, you want a Quadrajet.

If the carb is just getting old and sluggish, buy a gallon of laquer thinner, a non-plastic bucket and a carb kit. Disassemble the carb, re-seating and counting/ recording turns on all adjustment screws. Soak all non-plastic parts in the laquer thinner. Then, use chemical gloves and a non-plastic brush to clean. Blow compressed air through all passages. Put it all back together with all adjustments re-set as before.

That will probably have it running like new (a lot better chance than buying a new Holley). If you are unsure of your ability to do this, get it done by someone who knows how to work on them (which is admittedly getting harder to find). Ask around.

God bless, Sensei

 

If an overhaul of your existing Q-jet or a replacement Q-Jet is not on your option list, then a 4175(vacuum secondary, or 4165 mechanical secondary) Holley is probably your best choice. It bolts right up, uses existing hardware, and runs great out of the box. Not quite as perfect as the factory Q-jet, but comes without the fitment headaches of the squarebore carb options.

 

You might find this interesting.
CARBS Tests TQ/HP
http://www.corvettefaq.com/c3/carbcomparo.htm

 

There is no magic to getting HP/Torque from your carb. Carbs provide a set A/F mixture at a set CFM. As long as the carb is tuned correctly and provides sufficient CFM, it will give ultimate performance. Some are easier to tune than others, which is why one design may be better for race or dyno only use while another is better for the street/ strip car. Posting HP/Torque numbers from different carbs on a motor only shows which carb was set up best for that motor at the time. It in no way indicates which carb is better.

God bless, Sensei

 

I have to agree with a1sensei. Your not going to find a better carb than your original. Your best bet is a rebuild of your Q-jet. It really isnt as complicated as it seems and you will know what exactly you have and not wonder if what you bought is junk. Buy a book and a rebuild kit. I went with cliff's high performance for a rebuild kit and he matched it to my engine and even helped me out over the phone.

Saves a lot of money, and you learn a lot in the process...especially how to tune it yourself. I had absolutely no knowledge about carbs, but I made it through. I say go for it, but its up to you.

Sean

 

I went with the 4175, and other than trying some different secondary springs this thing has been flawless. Qjet had endless hesitation and by the time I got it worked out I had to fabricate a new pump rod which then came apart during a rally cruise and had to be re-fab'd on the side of the road. The 4175 solved all the frustration!

Now with that said, I'm not going to challenge A1sensei. I fully believe that he and the other Q-Jet experts can make that carb perform like they say. Problem is there are about 4-5 guy's in the whole country that can do it while also possessing the time and patience. The rest of us shade tree types are left scratching our heads.

I still have my Q-Jet and will undoubtedly tinker with it and put it back on at some point, but for a quick stable tunable fix the 4175 fit the bill! Plus I can switch back to the Q-Jet anytime without major re-configuration.

Thats my .02 for the day.

 

I'll take a Q-Jet any day over a VS Holley.

Why are you bent on a carb swap? Post the problem you're having and you'll get some good advice on this site.

 

Actually JET Performance set up both the Q-J & Holley 3310 for the engine & test to make the most power.
There is info. in that chart for those that look at it carefully.

If you guys get familiar w/ the carb you are running, you will find that adj. & tuning will yield better perf. even w/ the Q-J which is not hard to
adj., rebuild or tune.

 

so with the Edelbrock you set the screws while at max manifold vacuum? About what RPM is that?

 

You set your idle RPMs, then adjust the idle mixture screws to get the most vacuum at that RPM; Standard idle mixture adjustment procedure.

God bless, Sensei

 

I'm pretty sure there are more than 4 or 5 of us around, although I do have to limit the time I spend working on carbs in order to keep my wife happy (she likes to see me out of the garage from time to time). That's why I get on here and try to help the head scratchers. I don't have time to fix everybodies carbs myself, but if I'm in the living room telling you how to fix your own, I'm not out in the garage working on one, am I!

God bless, Sensei

 

Okay. so if i plan on rebuilding my carb myself, what would be the best way to go?

 

See my first post on this thread.

If the carb is having any specific problems, PM me and tell me what it is doing. There are also a few other things to check, but it will not be hard. Nothing beats the satisfaction of fixing your car yourself!

God bless, Sensei

 

I purchase a Qjet from Sean Murphy (Sean@smicarburetor.com) for my 69 Chevelle SS396. It was perfect out of the box. I would recommend chatting with him. He can send you a new carb tuned to your car or rebuild yours.
I also used a Holley 650 replacement carb. That would well for low performance pollution control cars. It would Create on my 75 L82 vette. But this carb has limited adjustments for the primaries.

 

I would definitely go buy a book on Q-jets for a rebuild. Pictures help a ton. Mine is written by Cliff Ruggles, which is also who I bought my rebuild kit from(cliffshighperformance). There are cheaper ways to go, but he did all the hard work for me and just sent me the correct parts. Basic rebuild is still great like a1sensei stated in his post. If your engine isnt stock you will need to make some changes to get it to run the best.

Also get a hold of lars q-jet papers. There is a lot of info on jet/rod sizes in there and a lot of helpful tips.

Sean

 

Yes,Sean re-built mine, like new.