carb recommendations

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68gtx

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looking for a new carb for my project, mild 360, edelbrock heads, performer rpm, intake and heads, 10:5 to 1 comp. roller cam, headers, 3000stall, and 4:10 rear gears, if needed I can get cam specs, street car, occasional street legal night at the strip, I think I want a mech secondary, thinking along the holley ultra series or a mighty demon, but I have no idea as to size, 650? 750? don't want something to big that makes it lazy on the street. what do you guys think, ??? size? mech sec or vac sec?
 
I see no problem with a mechanical secondary carb with your combo, stall, gear, etc. A 750/770 would be the logical choice, since I have to think performance is really in your mind with that setup. Nothing wrong with a 650/670 at all, but you'll probably leave a few ponies on the table at the big end. Either will be fine and streetable as long as their tuned in for your car.

I haven't personally used a "Ultra".....after my time, lol. But I do prefer the Holley over the Demon.



P.S. I should clarify, the 670/770 numbers were in relation to the Vac. Secd. Holley Street Avenger carbs that are available, incase you decided to go that route.
 
750 DP would be perfect. I also have a 750 dp that was just rebuilt and only has 300 miles on it that I am selling. Built by BIGGS Carbs. I am getting a bigger carb for my stroker and it will be E85 compatible
 
most cfm calculators call for less than a 650 cfm though.. which is a little misleading as most say a 750 will work well
 
I think any DP will be the wrong carburetor. If it was mine, I'd try one of them little new Street Demons on it.
 
You've spent a ton of $$ on hi-flowing accessories,, so restricting it with anything less than 750/780 cfm would seem counter productive...

Holley,, of course..

hope it helps..
 
A Holley style 750dp (Holley, Proform, Quick fuel, Demon) would be my first choice. If you don't need a choke (if you're not going to drive it in the winter), getting one with a HP main body would be ideal.
 
I love my Thermoquad.... picked up 5 mph in the quarter mile with my 850 TQ over the 750 Holley (vac. secondary)...
 
I have nearly the exact same combo as you. I switch between my Holley 750 dp and a Eddie 650 avs. The Holley took me up 4 mph at the big end but I still like the 650 on the street. If I had to just choose one though it would be the Holley!
 
flyfish said:
A Holley style 750dp (Holley, Proform, Quick fuel, Demon) would be my first choice. If you don't need a choke (if you're not going to drive it in the winter), getting one with a HP main body would be ideal.
Click to expand...

This is what mine is. Fully adjustable HP center etc
 
Get a Quickfuel Super street series 650cfm mechanical secondary carburetor. That's what I would run if it were me. I run a quickfuel super street series 680cfm vaccum secondary carb on my 360 magnum and I love it. Tuning is unlimited on these carbs.
you can change idle air bleeds, idle feed restrictors, power valve channel restrictors, High speed air bleeds, 4 corner idle circuit, And they are made of billiet aluminum. Definitely the best carburetor I have ever owned hands down. I say get a 650cfm because if its mostly a street car you will like the throttle response a 650 will provide on the street.
 
I personally go with one of the new fuel injection systems , or a 750 double pumper .

my 340 has a 750 dbl pmpr too
 
Look,, I've said this before,, if you spent that kinda bucks to make it go,, and have a dream of having your eyeballs pushed into your head...

Finish the job, and put a carb that's gonna show all the potential the motors got,, that's why you built a 360 and not a 318, bought alum heads,, not using old steel ones, changed the cam, and installed the headers for Cripes sake..!!!

Let it put a big ****-faced grin on your face.. ... then

If you find it too powerful, need better fuel mileage, etc, etc,, then de-tune it by putting on a smaller carb, knocking back the timing, and run regular fuel, Hell, put on a single exhaust and it will run FINE,, but find out what you built first,,

Think of it this way,..You've built a 4 inch air pump,, put on a 4 inch outlet,, now decide if you're gonna put on a 3 inch or 4 inch inlet...

hope it helps
 
Wow Grant your getting grumpy like me , LOL some people only listen when your saying what they want to hear . To the OP I'm running a Holley 950HP on my 410 stroker , it's a been a bit finicky tuning for low speed and Idle but when the pedal goes down the nose comes up and the eyeballs definitely go back into the soft mushy stuff in my head .
 
Holley ultra HP's are nice carbs. From what I hear, they are much better on fuel curve than the early hp style carbs. Not as fat off idle/cruise which is the biggest issue with the early HP's

I use those calculators as what's the smallest carb to run on an engine. Nothing smaller than a 750 on that engine, IMO.

Some recommend stuff that was generally accepted in the 1970-1980's. Now, things are a little different.
 
thought about upgrading to the Ultra but they cost 1k around here on sale which is almost EFI money so no go .
 
RustyRatRod said:
I think any DP will be the wrong carburetor. If it was mine, I'd try one of them little new Street Demons on it.
Click to expand...

x2
There's an interesting article in the August edition of Mopar Muscle comparing carbs. In the article on their 'BUDGET" built 360 it seems like they feel the Street Demon is the best bet for their engine.
Worth a read for sure.
 
the best performance will come from a holley dp....the 750 is the perfect size for the 360.....

the street demon looks nice...but i saw where you gotta take the carb off...and fill it over and disassemble the carb to change jets...just read ..you got to disassemble the carb to put the mopar throttle stud on it......

I will stick with the simple design of the holley....
 
There are some interesting videos and observations on the Street Demon on You Tube.
There are road and dyno tests of the carb on GM, Ford and the one that most interested me, the installation and road test on a 1972 Dart. The installation and testing on the Dart was done by a shop called ASAP in Gainsville, GA. The installation of the Chrysler stud looked easy to me, no need to take the carb apart. All of the videos I watched, the performance of the carb out of the box was right on, and very little other than setting the idle speed was needed.
Just thought you might find these videos and comments interesting to you.
Tony is right about changing the jets. You've got to take the carb apart to do that.
 
Since Holley purchased Barry Grant, they are making some nice products. I am really wanting to try one of the new street demons. They make a 750 now.
 
i have a 360 magnum with a hughes roller cam(544/228)rpm airgap,headers,391 gears,mvb(cope transmission)9.5 ptc convertor.and i run a holley hp 750 (vac.sec.)and i really like it.quick fuel reccommended thier q-750 d.p.but i went with the holley instead.both carbs are great choices
 
Carb manufacture aside, 750 CFM's is what I would use for the street/strip set up you got going there. True, a 650 is only a few ponies down on power in many cases, the side bennifit is throttle response goes way up.

The big issue here is what cam (specs please) your running and is there any porting done to the heads?
 
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