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Discussion Starter #1
1966 Nova 2 door hardtop
L79 clone
.040” over small journal 327
461 heads 2.02/1.6 valves bowls cleaned up
10.3:1 compression
280 comp hydraulic, [email protected] .050” .480” lift
Winters dual plane
1 5/8” headers, 2 1/2 exhaust
M21 , Centerforce clutch
Moser 12 bolt, 3.73:1 Posi, 24.75” tall tire

Car is street driven.
Presently a Holley 1850-2 vacuum 600 cfm

Car runs pretty well. Carb is tuned, still has a bit of the eye burner smell but the cam is fairly big for a small cube engine.

Thinking there might be some gains with a new carb.
650 double pumper? 750 VS?

Thoughts?
 

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With you're 4 speed I would go DP all the way . I have a 355 with a m21 in my 63 with a AED 750 HO DP and I get zero bog.
 

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I'd also go with at least a 650 DP and would probably go with a 750. If I could spend the money I'd also go ahead and buy a worked carburetor. Not a fan of vacuum carburetors. I've never seen one that a DP wouldn't speed up.
 

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If you are going to shift it high and have fun with it, I would say a 650 double pumper would be as big as I would go.
 

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I may be the outliar here, but if you're going to invest, a tried-and-true Holley 4150 750 DP is hard to go wrong with. It may be a hair on the big side, but if you're going to spend the $$$ now and want to grow later on, a 750 will leave you some headroom.

Worth noting, the Proform series of carbs are affordable and solid choices, too. As are the Quick Fuel Brawler line of carbs.

Leave time and room for dialing in the carburetor, too.
 

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Discussion Starter #7
From time to time I like shifting at 6000 or a hair higher.

I was looking for some fun factor as well and I understand that the mechanical secondaries kicking it can be a great kick in the arse if the carb is sized and tuned correctly?

So, If its you car, and you are going mechanical(double pumper) tell me the best choice. I do strret drive the car so some driveability is nice.....

600 DP
650DP
750DP
 

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Personally I'd keep the carb you have, especially if you drive it on the street, but I'm sure a 650 DP would be more than enough carb for that application. A bigger carb might not have the driveability of the 600/650.
 

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I may be the outliar here, but if you're going to invest, a tried-and-true Holley 4150 750 DP is hard to go wrong with. It may be a hair on the big side, but if you're going to spend the $$$ now and want to grow later on, a 750 will leave you some headroom.

Worth noting, the Proform series of carbs are affordable and solid choices, too. As are the Quick Fuel Brawler line of carbs.

Leave time and room for dialing in the carburetor, too.
You could also go with a 650DP and if you ever upgrade you can get a Proform 750 body and turn your 650 to a 750.
 

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Your car is beautiful!

If you're eyes are burning from exhaust fumes at idle, I'm curious about your ignition timing. Sometimes that's caused by not enough initial advance at idle.

Gerry
 

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Really like my Holley 670 Street Avenger, ran great out of the box. Holley prevented problems by limiting the adjustment!
 

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From time to time I like shifting at 6000 or a hair higher.

I was looking for some fun factor as well and I understand that the mechanical secondaries kicking it can be a great kick in the arse if the carb is sized and tuned correctly?

So, If its you car, and you are going mechanical(double pumper) tell me the best choice. I do strret drive the car so some driveability is nice.....

600 DP
650DP
750DP
Do the 650 or 750. Either will work fine if jetted and tuned properly. Was never a fan of Holly carburetors with 00's on the end either. I'd still do a worked 750.
 

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I have found recently carburetors have been hit or miss. Either they work well out of the box or they are a tuning nightmare and never seem to run right.
 

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Got rid of the plastic Super Tach II. Found a nicer one....haha
LOL - it appears we are building the same car sir. I have also rotated thru a couple SUN tach's before I got the one that I liked. Mines in the same spot but bolted thru my column shifter tab.:D:D
 

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Discussion Starter #20 (Edited)
Other than my auto meter gauges below the dash, all my speed parts are vintage. Wheels, tach, traction bars, headers, etc... So to stay with the theme, it’s gotta be a Holley.
 
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