Time For New Carb?

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icejawa

Well-known member
Joined
Oct 16, 2016
Messages
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Location
cleveland
My Car
1971 Mach 1 M Code,2003 Mach Azure Blue
Hey all,

I currently have an Edelbrock 1406 600 CFM carburetor on my 351C-4V. I have rebuilt the carb a few times over the years with official Edelbrock kits. The thing is all beaten up on the outside and I think I would love a new carb. Can anyone give me some advice? I have been thinking the Holley Street Demon 625 CFM Carb would be a great replacement but I would love to hear what everyone else thinks.

Engine is a stock 351C-4V with edelbrock intake manifold

Thanks

 
You have an M code 4 speed correct? You’re carb is undersized. I personally would be running a 750 with mechanical secondaries. A little more work getting it tuned properly but once it is makes a huge difference. This has been debated many times on here before. Due to head and valve design of the Cleveland they like a larger carb.

 
Good to hear I knew my engine was being choked out. The previous owner gave me that carb on the engine and I haven't replaced it since.

 
Quick Fuel makes a nice 750 DP. It is based on the Holley but slightly less expensive and IMHO a better carb.
 You took the words out of my mouth. If I was to replace my Holley Street Avenger 670, which works very well on my 351 C 4V manual trans car after a bit of tweaking / modifying, that's exactly what I would chose............. and at the same time, I think I'd spring for that Blue Thunder manifold  as well.

 
Also,

Wanted to mention that I have not heard great things about the Demon carbs. My biggest concern with their design is that with the smaller primaries you might get a slightly crisper throttle response at part throttle but with the oversized secondaries I have heard complaints about a bog or hesitation from several people when transitioning to WOT that can be a nightmare to tune out.

 
Would I want vacuum secondaries though if I am using it for just street use at the moment? I heard mechanical secondaries guzzle gas

edit: I suppose it doesn't matter since I'm not driving it every day

 
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Would I want vacuum secondaries though if I am using it for just street use at the moment? I heard mechanical secondaries guzzle gas

edit: I suppose it doesn't matter since I'm not driving it every day
I'd go for vacuum secondary's, but with a quick change cap ( red arrow) so you can change springs in a heart beat to get the response you want. In other words the "KISS" method.

Just my thought on it.

Geoff.

 
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Another option is to consider going EFI at this point. Its not a ton more than a carb. $800 for the 400hp unit and then add on another $200-300 for fuel pump and fuel lines. Its an easy swap as you can use the existing hard line and then use the fuel tank vent as the return line. Food for thought.

 
What do you guys think of the Quick Fuel Slayer 750CFM carb with vacuum secondaries? I was looking at the Street-Q Carburetor 750CFM VS which seems like a great choice but the slayer looks very similar for $300 compared to the $500 Street Q

 
What do you guys think of the Quick Fuel Slayer 750CFM carb with vacuum secondaries? I was looking at the Street-Q Carburetor 750CFM VS which seems like a great choice but the slayer looks very similar for $300 compared to the $500 Street Q
 Good reviews from what I found doing a quick Google search, Good price from Summit Racing and probably the one I'd go for IF I were changing carbs.

Others may have differing opinions who have actually used one. What I like is the tunability of Quick Fuel carbs as well as the price.

Update;

I did a bit more research on Summit's site and for a few bucks more you could go to the QF Brawler Street carb series which are double pumpers. I actually had no idea how many different types QF have, something for everyone's budget and need.

 
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Ill take a look at the Brawler, might also buy a new throttle cable

 
Ill take a look at the Brawler, might also buy a new throttle cable
Good plan. I found it a bit of a PITA to fit to the pedal and I'm a smaller guy!! Easy to take the seat out if necessary. While you're at it, perhaps a good time to upgrade your fuel lines as well. And the list goes on.............!

I have pics and info on my f/line upgrade if you need that.

 
Do you know if the Slayer Series 750CFM is also a double pumper like the Brawler? It has the dual fuel inlets it says on summit's site

 
Do you know if the Slayer Series 750CFM is also a double pumper like the Brawler? It has the dual fuel inlets it says on summit's site
The slayer is a Vac secondary. The Brawler is a DP or mechanical secondary.

Double Pumper is Mechanical secondary. It means there are two accelerator pumps, one for primaries and one for secondary's

 
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Ah ok. My only concern with mechanical secondaries is that I believe I have the vacuum line from the distributor to the vacuum secondary header. I have never used a mechanical secondary carburetor so I'm unsure how I'd install it on my current setup. Mechanical sounds way more beneficial though

 
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