to holley or not

[nmarlow 10]

any thoughts on changing my carburetor to a holley? I have a 69 conv.with a 351c 2 barrel. i have had to change it twice with rebuilt motorcraft. any good ideas? don't be too harsh as im clueless.

[wantahertzdonut 10]

Most of my friends have Holley's on theirs, they all seem pretty happy.

 

Mine came with an Edelbrock and I've been pretty happy with it. I had to rebuild it due to gas tank sediment getting in there but that was an easy job.

 

In my opinion you can't go wrong with either.

[70Mach03 12]

If you're talking about staying with a 2V carb and want more performance, I'd try a Holley 500 CFM 2-barrel carb. Many years ago I put one on a 302-2V and was very suprised with the performance increase. I also got slightly better gas mileage too since I didn't have to use as much throttle to get it going. I always thought they'd be perfect for a 351-2V setup without going to the added expense of adding a 4V intake and 4V carb.

[Pakrat 1,043]

I have always been a Holley fan for some reason, I think due mostly to nestalgia. When I was a kid in High School all the kick ass cars had holleys on them. You'll find just as many folks hate the tuning aspect of them as there are folks who praise their performance. Most folks these days seem to like Speed Demons for the little to no maintanence factor which may appeal to you. Alot of articles I have read these days though seem to be going back to the original Autolites claiming they are way overbuilt and actually a better carb for the money.

 

Holley does have a new carb slector proagram on their website which makes choices easier for the novice, just answer a few questions.

 

I have the holley 600cfm with vaccumm secondaries on a Weind intake and love the set up but it eats more gas for sure. If you are lookig for just another 2 barrell I'd kind of suggest a new autolite, if you upgrade to 4 barrell don't just do the intake too as the car needs to be able to exhale as well as inhale so you should consider some type of header or high perfomance manifold or atleast a good dual exhaust if you don't have one already.

[ForceFed70 14]

I've always said:

- If you want to install and forget get an edelbrock or speed demon.

- If you want to mess around with tuning it to get those last few HP and have it running "just perfect" then you'll want a holley so long as you know how to tune it or are willing to spend a bunch of time learning.

 

Personally, I never did take the time to learn and experiment with tuning my holley. I ended up converting to megasquirt EFI in the end, but if I was to go back to carb it would be an edelbrock/speed demon.

[bnickel 10,004]

I've always said:

- If you want to install and forget get an edelbrock or speed demon.

- If you want to mess around with tuning it to get those last few HP and have it running "just perfect" then you'll want a holley so long as you know how to tune it or are willing to spend a bunch of time learning.

 

Personally, I never did take the time to learn and experiment with tuning my holley. I ended up converting to megasquirt EFI in the end, but if I was to go back to carb it would be an edelbrock/speed demon.

 

 

my sentiments exactly. i'll add though that the Demon needs some tuning to get it just right but once you have it you're good to go, no need to fiddle with it every time the weather changes or whatever like a holley would. that said if you just want a 2 barrel replacement carb the 500 holley is a good choice. i think demon is also making 2v carbs now as well so that's worth a look too.

[bnickel 10,004]

just checked there is a 2v demon carb available.

 

http://www.barrygrant.com/demon/default.aspx?page=5a

[coz 108]

I've always said:

- If you want to install and forget get an edelbrock or speed demon.

- If you want to mess around with tuning it to get those last few HP and have it running "just perfect" then you'll want a holley so long as you know how to tune it or are willing to spend a bunch of time learning.

 

Personally, I never did take the time to learn and experiment with tuning my holley. I ended up converting to megasquirt EFI in the end, but if I was to go back to carb it would be an edelbrock/speed demon.

 

Well you know what they say about opinions... But here goes; Buy an Edelbrock if you want to lose - can't stand them. Nothing but problems and they flow like crap. I've had some experience with the Demons (speed and race) and was not impressed. Now a caviat - I have no experience with 2V or anything under 750CFM. So maybe these carbs work better if smaller or 2V.

 

I do agree that you will want to "tweak" a Holley to get the most out of them but they have always performed well for me out of the box. Right now I'm running a 950CFM ProSystems carb (Holley on steriods) and have to admit I've had some tweaking - mostly trying to find the right squirters to work. Right now the jets are 76 primary and 86 secondary. So you could say I'm running a bit rich. The engine was originally set up to run at 7k rpm for long periods - not exactly streetable. But when those barrels are open and it's above 4k - hold on tight for a wild ride. Am dropping the jets down to find the right street/strip combo. Also - no vacuum here - all mechcanical....

 

Have always heard the Holley Street Avenger 670cfm is a great carb for your type application assuming vacuum secondaries. But for Edelbrock - leave those blingy POS's to the Chebby crowd.

 

Again just my opinion.....

 

Happy Turkey day fellow stanger's

- COZ

[PaleRider 12]

I've heard the story edelbrock out of the box great but lacking tuning capability and Holley's need to tune but better performance possibilities. No where near an expert on this but 600 Holley with factory setting worked great on my 302 - I'm sure I can get more out of it with more tuning but current thought if it's not broke don't fix it. My guess is the debate between the 2 are more for the gearheads or track guys - for weekend drivers like myself - I don't thing it really matters. I would go with whoever has the better deal. They are both quality carbs.

[nmarlow 10]

I did but the holley 500 CFM, but now i need to find a gooood mechanic in my city of san antonio that knows what they are doing. anyone out there know any one here?? thanks nancy m.

[bnickel 10,004]

if you want a dead nuts reliable carb that you never have to jack with after initial adjustments the E'brock or Carter afb is unbeatable. i've never had anything but bad luck with holley carbs and they are always in need of adjustment every time the weather changes.

[ForceFed70 14]

I guess it's not fair to lump all holley's into 1 catagory.

 

My experience is with the 750 dbl-pumper. This carb was inteded for racing or street/strip use, and thus it makes sense that it'll require a little more tweeking than normal. Holley does make carbs designed more for the daily driver. Those carbs probably are more forgiving with tuning and out of the box tune.

[Cheo69GT 1]

I'm running a 670 Street Avenger in the 69 and I love it, works very well with the Weiand intake. My 68 has a 500cfm holley in it and I'm not sure about that carb, someone told me it's more of a track carb used by oval racers, good performance but a pain to tune.

[351carlo 10]

Would someone mind telling me aside from the aluminum CNC material and the new baseplates what the difference is between a 750 Speed Demon and a 4150 Holley? Aside from the obvious zinc coating and longer bowls on the Demon.... I thought they were the same.

[70Mach03 12]

any thoughts on changing my carburetor to a holley? I have a 69 conv.with a 351c 2 barrel. i have had to change it twice with rebuilt motorcraft. any good ideas? don't be too harsh as im clueless.

 

 

I thought the original question was to replace your 2-barrel on your 351C-2V? Like I had said earlier, a Holley 2-barrel 500 CFM carb would be a direct bolt on and you should see a nice performance increase. I used one for years on a 302-2V Mustang and I was surprised that my mpg improved slightly also....once I got used to the extra horsepower and started driving it normally.

 

I've used Holley carbs for over 30 years on 302-2V, 351C-4V, and 428-4V SCJ powered Mustangs I've owned. I've never had any problems and they are easy to work on and get parts for if you're the type who can't leave well enough alone (LOL). I would somethings swap out the jets depending on the tail pipe color (richer vs leaner) simply because it was easy and I could. They've always ran well right out of the box and probably 95% of the people would be satisfied, but the type of people who come to forums like this are like me and like to experiment and fool around with their cars and change things whether they need it or not (ha ha).

 

 

Bottom line......everybody has opinions but it's your car, your money, and your decision so have fun and do what YOU think is best, you'll have our support not matter what you do. :redface:

[369coupes 14]

i HATE holleys

elderock or carters are the only way to go every holley i ever had was total junk leaked fuel , wouldnt stay in tune ran rich blah blah blah a holley is a single purpose carb you either race it or street drive it not both , elderbrocks are awesome no gaskets below fuel level dont have to take the carb all apart to change jets /rods etc and no stupid ass power valve to worry about

[70Mach03 12]

I'm running a 670 Street Avenger in the 69 and I love it, works very well with the Weiand intake. My 68 has a 500cfm holley in it and I'm not sure about that carb, someone told me it's more of a track carb used by oval racers, good performance but a pain to tune.

 

I'm running a 670CFM Avenger on my 351C-4V also and picked up 10 rwhp over my generic 600 CFM.

 

They did make a Holley 500 CFM for race only but my street version with manual choke worked great.

 

 

 

Carburators are like anything else that has multipe choices, you will find some people who love one brand and won't try anything else. Many years ago I bought a new car that had Uniroyal tires on it. I had nothing but trouble with those tires and within 6,000 miles had replaced all four. To this day I refuse to buy Uniroyal tires even though I'm sure there are many people who swear by them.

[Cheo69GT 1]

I'm running a 670CFM Avenger on my 351C-4V also and picked up 10 rwhp over my generic 600 CFM.

 

They did make a Holley 500 CFM for race only but my street version with manual choke worked great.

 

 

 

Carburators are like anything else that has multipe choices, you will find some people who love one brand and won't try anything else. Many years ago I bought a new car that had Uniroyal tires on it. I had nothing but trouble with those tires and within 6,000 miles had replaced all four. To this day I refuse to buy Uniroyal tires even though I'm sure there are many people who swear by them.

 

The Weiand and 670 improved my 1/4 by .7, not bad, plus I got a dramatic MPG improvement.

[351carlo 10]

Would someone mind telling me aside from the aluminum CNC material and the new baseplates what the difference is between a 750 Speed Demon and a 4150 Holley? Aside from the obvious zinc coating and longer bowls on the Demon.... I thought they were the same.

 

Come on guys, back yourselves up. What is the difference between a Demon and a Holley for those of you saying they are different?

 

I'm very interested, having built both.... :sneaky2: Personal preference is understandable, but is there a difference or not?

[bnickel 10,004]

the basic design is very similar but the demon carbs are much more tunable, you can leterally tune every orifice of the demon carb as they alls use replaceable air bleeds instead of everything being cast in like the holley carb. also the throttle body is much more efficient than a holley throttle body and more consistent inside the throttle bores so the air won't shear inside the carb like it can on a holley. the billet metering blocks are worlds better than the cast zinc metering blocks of the holley carb also. basically the demon is a much refined version of a holley but there are enough differences in them that make them totally different carbs. the demon carb is better quality throughout than the holley carb that is one of things that makes them less susecsptable to weather/altitude changes and more sensitive to tuning.