Which Holley carb?

[bgarr01]

Hey guys I was wondering if the Holey 80457s Carb would be a good choice for a stock 350 79 Chevy C10? If not this one what one would be better. The street avenger is a little more than Im wanting to pay. Thank in advance.

[raceman6135]

It will work, but it is a square bore carburetor, and your stock engine will have a spread bore intake manifold. This means that the Holley 80457 will not physically bolt onto your intake manifold. You will need to purchase an adapter plate to make it fit.

Also, since the fuel inlet is different, you will need to invest a few dollars into the fuel line in order to mate the carburetor to your existing fuel pump and line.

Might as well set aside a few bucks for jets and accelerator pump squirters as you may need to tweak those to get the best performance and fuel economy from that carburetor.

You can buy a remanufactured Quadrajet for your engine that will bolt right on and be adjusted properly right out of the box for less than what a Holley 80457 will cost.

Just some food for thought.

[S10Fan]

A properly tuned Quadrajet is a good carb. The Holley Street Avenger is an awesome carb, I have 2 on 2 different trucks and couldn't be happier.

[bgarr01]

It currently has a Holley carb on it now model 8149-1. I've search a bit on the Internet and can't seem to find out about it. All the auto parts website says to go with the Holley 80451 but it's $350 vs the 80457 only being $250. The only real difference I notice is that the recommended one says it's street legal and will pass emissions. I live in Arkansas so I'm not to worried about emissions and what not. I guess I'm a bit confused.
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[bgarr01]

I migh add as well that the current carb on it isn't doing its job. Anytime you apply more than quarter throttle it bogs down and occasionally backfires.
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[cableguy0]

The street avenger would be the best choice but with that said the 80457 is a good carb thats been around forever and works well in stock-ish applications.


Now with that said theres probably no reason to replace your current carb. Most carburetor problems turn out to be timing issues. When is the last time you have done a tune up? Im talking cap,rotor,plugs and wires. Have you checked the timing? Can you better explain exactly what the truck is doing and when?

[bgarr01]

I recently bought the truck about a month ago. The previous owner said it sit in the field for 2 years. He told me he started it every now and then just to let it run. When I got it home, I did the tune up, plugs, wires, distributor rotor all that good stuff. I also emptied out the gas tank, it had a lot of gunk. At that point it would barely pull its self. I took it to a mechanic and he said he adjusted the timing and got most of it out. When you first start it, you cant give it more than quarter throttle without it bogging down with the occasional backfire. After it gets warmed up it seems to run much better. however it never really feels like it has any real power. Im new to all of this so I do appreciate all the help. SO far this site has been wonderful.

[cableguy0]

The carburetor itself likely needs a good cleaning and a rebuild wouldnt hurt. A rebuild kit is 30 bucks versus a new carb at 250+. With an engine that sat for that long in a field. Its going to extremely hard to be sure of the condition and to ever get it fully back to tip top shape. I personally would start with the basics. Do a compression test first and make sure that the engine itself is in good shape. You could end up chasing a ghost by bolting new parts on to a worn out engine that wont ever run right without rebuild or replacement.

[raceman6135]

Originally Posted by cableguy0

The carburetor itself likely needs a good cleaning and a rebuild wouldnt hurt. A rebuild kit is 30 bucks versus a new carb at 250+. With an engine that sat for that long in a field. Its going to extremely hard to be sure of the condition and to ever get it fully back to tip top shape. I personally would start with the basics. Do a compression test first and make sure that the engine itself is in good shape. You could end up chasing a ghost by bolting new parts on to a worn out engine that wont ever run right without rebuild or replacement.

Now that we know it's been sitting for so long, cable's suggestions are spot on.

The carburetor is likely gummed up and the gaskets have shrunk and are messing up the proper function of the carburetor.

Doing a compression check and leakdown test are also excellent ideas -- a new carburetor won't fix worn out valves, pistons and rings

[bgarr01]

Took to the mechanic yesterday after the recommendations of having the compression checked. He said everything checks out and thinks that the carb either needs replaced or rebuilt. I had looked before for a rebuild kit, and came up empty handed and was just going to replace it resulting in the question I asked. I have since found a rebuild kit and have it on its way. So lets hope that fixes it. Hopefully I can rebuild it myself, looks pretty straight forward. Any suggestions or tips?

[cableguy0]

Buy a bucket of berrymans chem dip carb cleaner. Leave the carb soak in it at least for 24 hours after you take it apart. After it soaks clean it off and blow compressed air through the passages in the carb. What were the numbers on the compression test?

[bgarr01]

Thanks for the tip. I'm not sure of the compression numbers. The mechanic just said the compression checked out alright.
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[i8tokyo]

The 0-8149-1 is a pretty small carb for even a stock 350. (450 CFM) The Street Avenger 0-80670 (670 CFM) would be the best way to go, sell the old carb to help make-up the difference. You should be able to get $50-75 for it off Craigslist, those are great carbs for a 6cyl.

[Hertzdaddy]

Did your mechanic look at the distributor and check the timing? A backfire sounds like it could be a timing issue too.
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[bgarr01]

Yeah he said he adjusted the timing. I think Im just gonna go with i*tokyos suggestion and get the 80670 street avenger and be done with it. If there's something else wrong with it, itll give me a good excuse for the wife that I need to upgrade.