Summit or Holley Carb??

[66FSTBCK]

My goal is EFI one of these days, but for now, I really want to get rid of my Edelbrock 600 cfm and for several reasons...manual choke, leaks fuel out of the air horn, etc. I have always run and Edelbrock on both of my '66 Mustangs so I don't have anything to compare it to, but I have also always thought my cars could surely run better.

I have heard a lot of good things about Holley and the knock off Summit makes. It seems like they have made them more "ready to run" and easily tunable for the average guy that doesn't know a lot about carbs. My new engine has a more aggressive cam than my old 289 had in which I originally bought that Edelbrock carb for. SO, would you all go with the Holley Street Avenger or the Summit Street/Strip version? Price difference is about $110. The Holley is a 670 cfm though compared to the Summit 600.

http://www.summitracing.com/parts/su...00vs/overview/

http://www.summitracing.com/parts/hly-0-80670/overview/

[2manyhobbies]

Not the summit carb, its a copy of the newer top plate design that holley came out with and was pretty much abandoned. Go with the holley, you'll have a buddy with plenty of experience to help tune it. Not to mention you'll be choking that 347 with only 600cfm. Even mine needs a 650. Plus you can get a better deal from a local guy where I bought mine. He's a holley expert and sells rebuilt ones with goodies on them for less money. Or, i'm actually looking at getting a new demon carb, they're sweet looking and tune the same as a holley. I'll text you his number.

[kechke]

Go with the Summit carb, it is a clone of the Autolite 4100 which is arguably the best carb ever made.

[2manyhobbies]

Originally Posted by kechke

Go with the Summit carb, it is a clone of the Autolite 4100 which is arguably the best carb ever made.

Not a good choice for a 347 stroker.

[ScottsGT]

Not quite a clone, but a hybrid of the two designs.

[66FSTBCK]

I've heard some good and some bad of the summit carbs. They do make a 750 in the summit. Is that pushing it a bit?

[ajzride]

I've got a summit 750 on a 357w, I've never raced it, but it seems just fine to me.

[JohnnyK]

This came up in a thread not too long ago.. I'm still unclear who makes the Summit carbs? (I mean, it will be a rebranded carb.. But whos brand? Did anyone ever find out?).

[66FSTBCK]

I have heard it is a Holley rebrand and actually still assembled by Holley, but with the Summit name. Must have been a patent that ran out or a discontinuance of a design that Summit thought they might be able to take advantage of. It looks identical to a Holley in many ways.

[mph65k]

Glad to hear your 347 is running well. If you recall, I also recently got my 331 from Blueprint. So far so good, will be continuing some tweaks and upgrades. Tuning, transmission, rear end gearing, etc.

I'm running a Demon, Speed Demon 575, manual sec, no choke. Had it on my 289 Hi Po and now on my 331. I switched from a Holley and like the Demon a lot better. Plus as Hobbies mentioned, it is a nice looking carb to boot.

Can't comment on whether it's easier or harder to tune than others. Seemed like my Holley was a pain, but it probably needed a rebuild.

[kenash]

Originally Posted by 66FSTBCK

My goal is EFI one of these days, but for now, I really want to get rid of my Edelbrock 600 cfm and for several reasons...manual choke, leaks fuel out of the air horn, etc. I have always run and Edelbrock on both of my '66 Mustangs so I don't have anything to compare it to, but I have also always thought my cars could surely run better.

I have heard a lot of good things about Holley and the knock off Summit makes. It seems like they have made them more "ready to run" and easily tunable for the average guy that doesn't know a lot about carbs. My new engine has a more aggressive cam than my old 289 had in which I originally bought that Edelbrock carb for. SO, would you all go with the Holley Street Avenger or the Summit Street/Strip version? Price difference is about $110. The Holley is a 670 cfm though compared to the Summit 600.

http://www.summitracing.com/parts/su...00vs/overview/

http://www.summitracing.com/parts/hly-0-80670/overview/

Hi,
If you want real performance, gather your engine specs (details) and contact ProSystems. You'll get a carb that runs perfect "out of the box" and custom designed based on your specs. My junk is a strong running 334 and a 680 custom Holly XE added to it's great performance.

[Franks68coupe]

I have the summit 750 on mine, it's for all intents and purposes a Holly. The carb itself seems solid... all of my problems with it are user error. I have 0 experience with carbs, and am having a hell of a time getting this thing tuned. If you like tuning... this is your carb... if you're less experienced, and don't want to waste your weekends futzing with it, then keep looking.

[dav65mus]

I have been running many different types of carbs for the last 30 years. I have become a big fan of the annular booster carbs from quickfuel. (they are an upscale holley type carb) The annular boosters which were what was in the autolite 4100, are also in the summit carbs, and some demon carbs work very well at taming the rich idle produced by lopey low vacuum performance cams. The annular boosters atomize the fuel better with a lower vacuum signal and on my motors produce a much crisper throttle response than any edelbrock, carter, or downleg booster standard type holley ever produced even when tuned perfectly with an afr meter attached.

You pay a little more for a good quickfuel annular ( about $550 for an ss model) but as you come to find out over the years in performance equipment you usually get what you pay for.

Someone suggested pro systems for a carb also. They will ask for your engine specs and send you a carb that will be almost spot on out of the box for your motor with jetting and power valve, but will probably cost more than the annular quickfuel which you can easily tune yourself. If you have the cash pro systems is an excellent choice.

Also I will share my carb sizing findings from my 331 that was built by Keith Craft. It was super mild with only afr 165 heads, 10.4 compression, regular rpm edelbrock intake, jba mid length 1 5/8 headers, 2.5 inch exhaust and a tiny crower cam ( grind # 15510) with only 212deg @ .050 and 275deg adv. with .531 lift on a 114 lsa. This cam is suggested as a good idle stock 5.0 HO replacement cam in a 302 not for a 331!! But I wanted a smooth idle and lots of low end tq.(It idled like a stock 5.0 at 650 rpm when warmed up). The carb was a 600 holley dp set up and tuned by Keith when he dynoed and tuned the motor. The dyno results showed that the carb was a significant restriction from being too small from 5200 rpm up. I was the one who specd the tiny cam, heads, and carb.... Keith would have gone afr 185, larger cam and 750 carb. I still would have had great idle quality and an extra 50-60 hp. (it dynoed 386 hp/405tq at the flywheel with my crappy cam/heads/carb)

The moral of my expensive underpowered stroker build for your motor is simple. On a 347 you need a 750 carb since my mild 331 showed a 600 was way too small for it on a dyno tune.

I did correct my errors on my 331 before I sold the 65 fastback it was in. I replaced the heads with afr competition ported 185's, installed an fti cam from ed curtis, a vic jr intake, 750 quickfuel annular, 1 5/8 hooker longtubes with full 3 inch exhaust. The car still idled good had a nasty performance growl out of the exhaust and you needed a neck brace on when you hammered the throttle in it.

[66FSTBCK]

Sounds like most agree I need a larger cfm carb....bigger than 600. I like the looks of both holley and demon but I want something that I can learn to tune and not have to do it every weekend. I have a little bit of a credit from Summit so I think I want to buy one from there or look into the guy hobbies suggested. Is the design on the summit street strip just different than the holley street avenger?

[bartl]

Holley O-4779C