351c- what carb?

[cazsper]

I am stuck between rebuilding my Holley 650 double pumper or buying a new carb. I'm considering a 750 but not sure. I actually prefer a vacuum secondary with an electric choke.

Right now, my engine is a 351C with 4v heads, 224/230 @ .050", Torker intake (soon to be an Air Gap), C6 with 3.73 gears (soon to be 3.25).

I've been told mechanical secondaries aren't idea for the street. I've also been told a 750 is perfect for a Cleveland. Any ideas?

This is the carb I was looking at. It doesn't have any jets. Does anyone have experience with this type of carb?

This Review Holley 0-80508S Model 4160 750 CFM Square Bore Vacuum Secondary Electric Choke Replacement Carburetor This carburetor features a vacuum secondary with a metering plate that has no jets, power valves, or accelerator pumps which makes it easier to tune than full race carburetors with temperamental secondary metering blocks and dual pumps. It mixes the right amount of gasoline with air so that the engine runs properly. It is calibrated for gasoline and engineered to improve performance….

The Holley 0-80508S Model 4160 750 CFM Square Bore Vacuum Secondary Electric Choke Replacement Carburetor are best quality product. Its also a good product for the price. You can read each testimony from consumers to find out more from their experience. The reviews will give you a solid indication of the value and reliability of the products.

 

[Jeff73Mach1]

A 750 is probably about right and vacuum secondaries would be better for the street with the 3.25 gears. Your torque converter stall speed is also a factor to consider. One of the problems with the formulas is that they don't measure "Wet" flow. air and fuel laden air do not behave exactly the same.

Your 650 would probably be fine, even though it is a double pumper, if you will take the time to match the jets and accelerator pump cam to your car's needs.

Unfortunately most people bolt on a carb, tune it by ear, vacuum gauge, spark plug reads and seat of the pants feel. This can get you in trouble if you lack the experience to evaluate the evidence properly. Without monitoring exhaust gas throughout the rpm and load range, it is hard to really know what you need to change. for this a wideband O2 sensor and gauge is really the best way to go.

 

[kidwithfastback=fast]

I would go 750. Those 4v ports are big enough.

 

[Don C]

I have a Holley 750 w/vacuum secondaries and electric choke on my '71 351C-4V, also with 3.73 rear end and C6. It runs very well, just not good for high speed freeway driving, but great on winding roads. I plan on upgrading to a AODE-W this year.

 

[goodnigh]

Originally your basic 4V Cleveland came with a 600 if I am correct.

My 4V has a Holley 770 Street Avenger I am happy with it.

Something like this http://www.summitracing.com/parts/hly-0-80770/overview/

Order one from Summit Racing before 5 pm and you get it the next day, free shipping.

They have an outpost in Nevada.

mike

 

[cazsper]

Don,

Not perfect for highway driving? That's because of the 3.73's, right?

I was actually looking at this one. But I've never heard of a carb that doesn't have jets.

This Review Holley 0-80508S Model 4160 750 CFM Square Bore Vacuum Secondary Electric Choke Replacement Carburetor This carburetor features a vacuum secondary with a metering plate that has no jets, power valves, or accelerator pumps which makes it easier to tune than full race carburetors with temperamental secondary metering blocks and dual pumps. It mixes the right amount of gasoline with air so that the engine runs properly. It is calibrated for gasoline and engineered to improve performance….

The Holley 0-80508S Model 4160 750 CFM Square Bore Vacuum Secondary Electric Choke Replacement Carburetor are best quality product. Its also a good product for the price. You can read each testimony from consumers to find out more from their experience. The reviews will give you a solid indication of the value and reliability of the products.

 

[wwhite72]

If you have an auto trans you want vac secondaries with Ford kickdown. Electric chokes work fine on our cars. A 750 would be fine on a Cleveland, expect to do some jetting work to get best performance on any carb. And also, whoever sent you info on that 4160 is a clown. Just look on the Holley site for info and buy a new one from Summit and you will be happier. Of course the 4160 has jets !

 

[MeZapU]

I put a brand new Holley 750 VS on my engine after its rebuild. It still wanted more fuel under light acceleration and required non standard modifications. I fiddled with it for quite some time and was never truly happy. I sent it off to a custom carb specialty shop like http://www.prosystemsracing.com/rebuild.html and it came back looking better than new and ran flawlessly. Even picked up about 20-30 horsepower.

It is a tough pill to swallow but I consider them to be a poor mans EFI because the carb is now calibrated to YOUR specific engine and car combination. Its amazing what they can do these days with carbs in the care of a professional shop. I even have another one of their custom 4150's on my 1985 GT's 408ci. That thing is a monster but it still has plenty of street manners. Custom carbs are becoming the way to go as one size fits all, out of the box carbs, only sorta work well on near stock engines.

I'd buy a beat down 750 DP and send it to these guys. They will replace just about every component so it doesn't matter what it looks like as long as the castings are in good shape. For $400 it will come back being 100% ready to go and run better than any stock $450 carb you could ever hope for.

 

[Mister 4x4]

I'm still more of an Edelbrock fan over Holleys - you might check into the 750 Performer. Drop it on and not worry about it.

But - Holleys are good, too. I just prefer not having to mess with a leaky carb over time.

 

[cazsper]

Thanks I appreciate it. The DP I have is a 650cfm, though. I've only had experience with two edelbrock carbs. Each of them had a stumble right at the beginning.

 

[Luke]

Holley or quickfuel carbs over edelbrock for me. Only because my best mate is crew chief for pro racer,he does the tuning for me and these are the carbs he likes

 

[Don C]

Don,

Not perfect for highway driving? That's because of the 3.73's, right?

I was actually looking at this one. But I've never heard of a carb that doesn't have jets.

This Review Holley 0-80508S Model 4160 750 CFM Square Bore Vacuum Secondary Electric Choke Replacement Carburetor This carburetor features a vacuum secondary with a metering plate that has no jets, power valves, or accelerator pumps which makes it easier to tune than full race carburetors with temperamental secondary metering blocks and dual pumps. It mixes the right amount of gasoline with air so that the engine runs properly. It is calibrated for gasoline and engineered to improve performance….

The Holley 0-80508S Model 4160 750 CFM Square Bore Vacuum Secondary Electric Choke Replacement Carburetor are best quality product. Its also a good product for the price. You can read each testimony from consumers to find out more from their experience. The reviews will give you a solid indication of the value and reliability of the products.

Mine also has the metering plate for the secondaries. About the only adjustment ever needed for the secondaries is the throttle plate opening.

I did install the adjustable jet block on my primaries, makes it much easier to adjust the jets.

And you are correct, the rear end ratio is too low for sustained highway speeds, not to mention gas mileage.