305 carb issues

[Tom Sawyer]

Hello all... proud owner of a 1980 c10 Silverado with the just okay 305 engine. It only has 53K miles on it but, and not all will agree, it’s power output, and more specifically, it’s carburetor behavior is finicky, to say it kindly. A couple of real old school mechanics near me have suggested an Edelbrock intake paired with a Holley 650 carburetor will end all need to constantly adjust, to no avail, what they regard as one of GM’s poorest carburetors. They acknowledge that power output doesn’t jump significantly, it just runs more constant. I would love the thoughts of forum members that have any experience on this.
Thanks
Tom

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[Old60Driver]

Firstly, beautiful Silverado!

Secondly, can I assume you have the Rochester Quadrajet? I can't speak from personal experience, as I'm embarking next week to pick up my first square body. A completely stock 1983 K20 with a quadrajet installed. During the process researching how to put a little pep in her step, I came across a book by Cliff Ruggles, "How to Rebuild and Modify Rochester Quadrajet Carburetors". He's evidently the Yoda of the Quadrajets. He absolutely SWEARS by the quadrajet. And is actually a pretty fun guy to talk to to boot! Anyway, it might be worth a $50 dollar rebuild as opposed to a new intake/carb. That's MY plan anyway. lol

Good luck!

 

[Paladin]

Save yourself a lot of future headaches and frustration and listen to the old mechanics...get the HOLLEY!!! A beautiful square like that deserves it!

 

[gotyourgoat]

I do not condone the bashing of quadrajets.

Might as well sell that chevy and buy a ferd.

This thread is dead to me.

 

[Paladin]

Hmmmm.... seems some folks don't like it when your opinion (which I believe you are still allowed to voice under the Constitution) about something doesn't coincide with theirs, or that their opinion is the only one that matters! Reminds me of some organization, hmmm. what is their name, oh yeah, BLM for short! Nobody here bashing a q-jet, although I personally (just my opinion) think they are a hunk of junk. I was only responding to the OP requesting thoughts on the matter!

 

[Tom Sawyer]

Thank u folks for the compliments on the truck and I value all opinions. If one doesn’t want an opposing opinion, then one shouldn’t ask the question.
That said, 2 things...first, GM all the way for me. I’d buy a dodge before a ford.
And second, I’m probably gonna get the intake and Holley... May add a set of headers too. Breathing better is always a good thing.

 

[bedwards]

The Quad was made for the truck. If your keeping it stock like I did mine, there really are no better options. Having said that, I have rebuilt mine twice in 4 years before I got it right. I dare say mine runs as close to FI as your going to get with a carb. There are sites on the web that will tutor you on how to tune it right.

 

[Rusty Nail]

Well,
I am very curious.
Curious about which Quad you have.
The best carburetor I ever owned was a 795cfm Quadrajet on an L69.

L69 being an H.O. 305.
But it had WAY BETTER #416 heads (58cc) on it AND better compression. 9.5:1 AND a WAY better camshaft.

I wager your 1981 model 305 has lower compression and not NEAR as good #601 heads on it (53?cc). It's probably an LG4 with a 625 .
But it MAY be an LE9. They had #201 heads that really suck

I can.not. advise you correctly without more information.

Tom i'm gonna need the cylinder head casting number, the block casting number, and the carburetor model number. You'll have to spend some time and money IF you want a correct answer from me.

OR

You can ask a crowd of strangers on the internet what they think is the coolest way to waste your time and money.

But that's not what i'm about.

What are YOU about, Mr.Sawyer?
This will be the best aide to narrowing your extremely broad line of questioning.

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My thoughts are that a Quadrajet is one of the BEST carburetors EVER.
I also think a 1981 carburetor requires rebuild. -not even gonna look. Put a kit in it.
I also think your "old school mechanics" are scared of a quadrajet and are likely not mechanics at all. They get paid to sell and replace parts which they believe qualifies them as "mechanics".

"Service shops" MUST sell new parts.
Think about it Tom.
Putting on brand new stuff carries no liability and requires nothing more than a few tools.
I ALSO think they dont know wtf they are talking about AND they are ******* that may ALSO be stupid.

I ALSO think gm started installing aluminum intakes under quads in 1983 and they kind of kick ass AND THAT would be 1000x cooler than any new Edelbrock piece of **** that you can buy brand new.
I ALSO think a Holley "Contender" IS the period-correct aftermarket intake for your truck and THAT would be 10000x cooler than a 1983 aluminum gm.
WELL, MAYBE.

What are you about Tom?
We have many answers and opinions.

It needs better compression BEFORE it is going much faster. A better foundation is needed to build on.
The camshaft is a #2 pencil and youre sittin pretty @8.3:1 which blows AND sucks.

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[WebMonkey]

i bought a re-manufactured q-jet and the truck starts/runs/drives reliably/consistently.

unless i thought i'd make a crap load more ponies, there's no way i'd swap intakes and get a different carb for my normal/everyday 1985 k20.

i don't adjust squat on the q-jet.
set the vacuum and idle and haven't touched it since.
(ran fine out of the box but idle was a little high)

 

[Rusty Nail]

Yeah his needs rebuilt.

At least tighten the mounting bolts and airhorn screws.
Oh 1980?
Yeah...thats a pile.

Sounds like he's got some part swappers messin with his truck. No tellin what they did to it so they could sell him shiny cool parts.

Come on with the numbers Tom.
I can help you but you'll have to buy valve cover gaskets.
201s turned into 191s and that aint sayin much.

 

[M00SE]

Hello all... proud owner of a 1980 c10 Silverado with the just okay 305 engine. It only has 53K miles on it but, and not all will agree, it’s power output, and more specifically, it’s carburetor behavior is finicky, to say it kindly. A couple of real old school mechanics near me have suggested an Edelbrock intake paired with a Holley 650 carburetor will end all need to constantly adjust, to no avail, what they regard as one of GM’s poorest carburetors. They acknowledge that power output doesn’t jump significantly, it just runs more constant. I would love the thoughts of forum members that have any experience on this.
Thanks
Tom

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I agree with just about every post from others on this one... except the haters. Nothing but chevy for me but the one 305 I had (just gave it to my 18 year old niece for her 86 blazer) ran kinda like your saying.. I got a 600 cfm Edelbrock and its never ran better. Just my 2 cents.

edit-
I never had anything but problems with Holley.. lots of problems that seem to always come back again and again.

 

[Rusty Nail]

I agree with just about every post from others on this one... except the haters. Nothing but chevy for me but the one 305 I had (just gave it to my 18 year old niece for her 86 blazer) ran kinda like your saying.. I got a 600 cfm Edelbrock and its never ran better. Just my 2 cents.

edit-
I never had anything but problems with Holley.. lots of problems that seem to always come back again and again.

Pretty cool you call me a hater and spit hate two.periods. later.

Edelbrock carburetors SUCK
Lets argue on the internet.
U wanna race or fight?
Lol
Everybuddy gets a mettel, dunt b sad.

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[Tom Sawyer]

You guys take this stuff way too seriously.
Rusty Nail.... lighten up. I’m 58 years old, feel lucky to have a few toys and a few bucks to waste on them if I feel like it. Calling people ******* and stuff? Grow up. Go take a hike in the mountains, pet a dog, watch a sunset....something, anything to take that edge off.
I’m getting the intake and carb because I feel like it. If it sucks, I’ll get something else.
One last piece of advice, (comes from my dad), if you don’t have something nice to say, don’t say anything....please!

 

[Goldie Driver]

Well, I am pro QJet, but probably more because that is the OE carb although I have had many GM vehicles with them and few issues that I recall.

The one on Goldie needed a rebuild shortly after I got her - they had to drill out the original rivets when they did it.

38 years ain't too shabby.

But, I am not a mechanic, and not a hot rodder, so my opinion is just that.

Of course, if you do a different intake you can eliminate the EGR and a whole slew of vacuum hoses should you choose to.

Best of luck!

Britt

 

[Ricko1966]

The quadrajet ran beautiful when new.IMHO when people say they put a (insert brand here) carb on it and it ran so much better.Thats because they are comparing a new carb to a worn out one that wasn't functioning correctly anymore.No one takes off. a running like new,properly adjusted Quadrajet just because.They get taken off because they are having a problem. Your Quadrajet rebuilt, will be very reliable and economical,and 100 percent designed to work on your truck..