Well, since you have your mind made up, and you're bypassing some of the best choices, I'll just leave you to it! =)

I hate straight leg boosters in the primaries for street engines.

 

Mind is not made up just have some initial preferences. I’m no carb guru, that’s for sure and by means of this post soliciting opinions.

Seems you like the Quick Fuel & Brawler—which is better. Are there better choices…?

I‘m in the carburetors are self sizing camp “within reason“. I wouldn’t run mechanical secondaries with a C4 unless you have a really loose converter.

I’m lazy, I tune with an iPhone.

It will be a 4R70W w/a 2800 stall. I’ll make a final decision on stall once we assess the dyno graph.

 

I‘m in the carburetors are self sizing camp “within reason“. I wouldn’t run mechanical secondaries with a C4 unless you have a really loose converter.

I’m lazy, I tune with an iPhone.

 

Here is the result of the Summit Racing carburetor calculator

 

Bought a brawler last year and was very disappointed… I find it hard to believe that the carb was even test run.. gaskets at supply lines were smashed, fuel bowl height was way off… Got all that fixed but am still not happy with the performance. Good luck with your choice

 

I run the Holley 750 HP on a stout 383 in my 69 Camaro, and the 650 HP on a DZ 302 clone in my 57 Chevy. Both have been great carbs and are easily tuned. Given your build, I think you’ll be very pleased with the 650 for street application. On the 363 stroker in my 66 FB, I went with FiTech FI from the get go, so can’t help you there.

 

Was the 750HP vacuum or mechanical secondaries behind what trans…?

 

I have been running a Brawler 650 race, vacuum since 2017. Love it, runs great. It does have down leg boosters and is mostly made of aluminum. Tight machine work, quality carb. Adjustable air bleeds. I could list many superlatives about this carb. Look closer at it.

 

I’m nearly ready to fire up the new build and need to top it off with a carb. Since Holley is running a special now is the time. By preference alone I favor a 650cfm, vacuum secondary with adjustable air bleeds. Doesn’t matter much to me if it has an air horn/choke—I can do without. I also planned to keep the PCV system & power brakes so I need vacuum ports.

What I’m finding is Holley has no such beast unless I run a 750cfm which seems too much for a street 331 stroker. However, Quickfuel & Brawler do, but not sure how good of a carb they are in comparison—I only want to do this once.

Whatever I pick will be dyno tuned (w/wideband) which is why I favor the adjustable airbleeds, otherwise I’d probable just go w/a Holley Ulta 670 SA.

Here’s my initial thoughts;

1. HOLLEY ALUMINUM STREET HP CARBURETOR 750 CFM - 4150 - Vacuum Secondaries - adj air bleeds. This seems a little big for my application and dont want to hurt the street manners, air speed or furl atomization. I like this one ☝. Seems to me air speed past the secondary is important to keep up, but how much of a difference is there when you can change springs.
2. 650 CFM BRAWLER STREET CARBURETOR VACUUM SECONDARY 650 CFM - 4160 - Vacuum Secondaries - adj air bleeds & elect choke. This seems like just what i needed but I have zero experience with what I believe is a value line of carbs.
3. Quickfuel HR-SERIES CARBURETOR 680CFM VS - 4150 - Vacuum Secondaries - adj air bleeds & elect choke. Same as the brawler, but wondering which is better between the two.
4. HOLLEY ALUMINUM STREET HP CARBURETOR 650 CFM - 4150 - Mechanical Secondaries - adj air bleeds, no choke. Based on size alone and my experience with Holley, this is my preference, but concerned this paired with an automatic may be a bad choice. I’ve read plenty of threads indicating a DP is fine w/an auto if tuned, which it will be.

This is primarily a performance street build, specs are:
331 Stroker, AFR185 Renegade, port matched RPM AirGap, 10.2:1 w/Mahle flat tops, Howard’s roller cam 278/286, @ .050: 225/233, Lift: .560/.565, LSA/ICL: 112/108, FPA headers w/2.5“ dual exh all paired to a 4R70W w/a stall assumed to be around 2800rpm and 3.55 out back in the rearend. Im expecting the cam to perform up to 6500rpm. I’d consider the ‘68 Coupe somewhat light with me & fueled up around 3500lbs.

What say you guys on the above? What would you pick; vacuum secondary or mechanical.

If you decide to go with #3 I've got a used one I'll let go pretty cheap.

 

That offer will move it up on the list for sure!

 

I run a Quick fuel 650 mechanical secondary carb on my 302 w/ 5 speed and it feels right at home. Not sure how it would work out in an auto but with the right pedal modulation when going into the secondaries, I dont think it should present much issue.

If its going to be dyno tuned. I would go for one with replaceable bleeds and such. I would probably pick the Quick fuel 680 over the brawler 650 only because of the rear metering blocks offered in the 680. It'll make dyno tuning the secondary jetting a whole lot easier than the brawler imo. It also has 4 corner idle should your cam be hairy enough to need it.

 

Lots of people have success with specialist carb builders as opposed to buying box stock holleys/ quickfuels. Something like this from AED would be perfect:

https://www.aedperformance.com/ho-street-strip-carbs/ho-series/aed-650-ho-detail.html

 

Another vote for the Summit 4010 “style” carbs. Make sure you clean them out before use (as with all carbs IMO).

I like mine. There are some QOL improvements that you can make to it, but hard to beat it for a street car

 

personally i would not put a Holley on a street car. on a race car great.
I am running a pair of 1902 edelbrocks (500 cfm AVS2) on a 289 and have not changed a thing since i put them on 10,000 miles ago. i can get 24 mpg on the road and around 20 around town. of course it is different with all 8 barrels open.
it runs great.

 

The Summit has some nice features but quality is spotty. Plus, like Edelbrock it has a built in problem (integrated float bowls) making them more susceptible to heat soak than the 4150/4160 Holley based design. I tried one and sold it.

I have a Quick Fuel HR series, which I believe has been replaced by the Brawler. Note there are two Brawler series, one with cast main body and one with billet. Mine is manual secondaries, but with a manual transmission. With an automatic, I would go vacuum secondaries. Quick Fuel has a nice secondary vacuum adjustment to avoid messing with springs.

 

Quick Fuel has a nice secondary vacuum adjustment to avoid messing with springs.

Yup. installed one and it was great for finding the optimal opening rate for the secondaries that might have otherwise been impossible(or harder) to achieve with a holley spring kit

I have driven about 32,000 miles with a Holley 600 and another 4000 with my new double pumper and have yet to encounter catastrophic fuel leaks that everyone keeps warning about with holleys. Maybe its luck on my end or maybe its blown out of proportion or maybe people need to look at their carbs more often as a part of a routine maintenance schedule. Plus I get great gas mileage and personally an edelbrock doesn't look right in a vintage mustang engine bay

 

they sure do work well.
try to get 2 Holley's under a 14" air cleaner

 

I took a cheapo Holly 4bbl and sent it to Jet Chip Performance and they built me a custom carb matched to my cam shaft specs, head flow, rear end gearing, and transmission ratios. Can definitely recommend.

Custom Carburetor Specification Form – Jet Performance Products

jetchip.com

 

"Blueprinted" Summit 600, unless you can find a good, rebuildable Holley 4010.

 

Lots of people have success with specialist carb builders as opposed to buying box stock holleys/ quickfuels. Something like this from AED would be perfect:

https://www.aedperformance.com/ho-street-strip-carbs/ho-series/aed-650-ho-detail.html

Excellent idea, called AED & Holley and wouldn’t you guess—received two differing opinions. Maybe carb selection is part voodoo…

Holley recommended the QuickFuel 650 Downleg vacuum secondary w/billet metering blocks.

AED suggested their 750 HP/HO mechanical secondaries.

hmmm…seems I’m back to where I started. Maybe then im back to #3, the QF 680 Vac Secondaries

 

These guys might be worth a call, too. Home - Pro Systems Racing Carburetors

 

I still like my carbs. and they look cool. Now if only i could find a pair of small stellings and hellings air filters.

 

Stelling & Helling Air Cleaner

store.cobranda.com

 

If you like the Holley Street HP, Edelbrock makes a very nice 4150. The VRS-4150 650 has almost everything you want (air bleeds and PCV) but still has straight leg boosters And is a double pumper. It’s a little pricey but seems like a solid contender. If you like to tune, you‘ll like the 4150 style.

 

Re: heat soak in Edelbrock. This is true for me. I run a 750 performer (it runs great and has no bog anywhere) but it’s easier to start cold than after a good drive. I’m in the same process of looking for a new carb. I’m leaning toward a 650 Holley. 650 Street HP made my short list but may end up getting the 0-80783C (Vacuum secondary 650).

 

Heat soak is an issue with all carbs.i know someone with a sbc with a very expensive holley HP how was having this issue. He put a plate between the carb and the manifold it seamed to help. Any carb will be better with a heat isolating spacer.
I done think the problem is the carb type or brand it is the fuel it boils at low temps.
new cars dont have these issues as they run pressures high enough to prevent boiling.
Some times the fix may be to run a return line back to the tank with a return style fuel pressure regulator between the carb and the return line. This will keep the fuel moving and allow hot fuel to return to the tank.

 

In general, a smaller carb will perform better on the street. In my experience, most people run a too-large carb for Street use based on assumption that bigger is better. Unless you plan to run extended high RPMs, I would go with a 600 or 650 (max) CFM.

There are pros and cons to different brands, so do your research. Everyone here will be biased, so take opinions with caution. I like Holley and have run in my Mustangs for 41 years and like them but they are far from the only good option. Anyone who bashes Holley does not understand how to tune a Holley. They can be excellent street carbs That said, I will not say to only consider Holley. Again, find what works for you.

 

Go with the 750 Vac secondary carb. I run a 3310 780cfm carb . Its not too much

 

You run a 780 on a 428CJ?