Ok so how about a demon?

What's the matter..........own stock in Holley?Angry that they're in financial doo-doo?Todays Holley is but a shadow of its former self.

Everytime you open yer yap(post) the aggregate I.Q. of Club Cobra drops 20 points.%/

Why does it bother you so that i'm much cooler than you?**)

JHV48-do a search on this site about carbs.Plenty to read.Out-of-the-box Holleys AND BGs have been known to have metal chips in them.Lack of QC.Pro-systems is another option.Theirs is Holley based also.

Did you mean "merchant of TOOL"?:LOL:

Holley
 

I'd do a 600 vac or dp. I have a 650dp on an afr headed small block 302. Rpm air gap intake. You can run a little bigger carb on a dual plane intake. Three Holley's in the last three years and they all been perfect out of the box. You won't go wrong with a Holley. JMO.

later
dennis

Yeah, just like the originals had Edelbrock manifolds and heads! I run a Holley 670 because that is what my engine builder said would be the best carb for it. BTW-operation has been flawless so far in over 3000 miles.

My 800 DP spreadbore came used off a TransAM race car and served me well for 40 odd thousand miles. Yes, I've replaced gaskets and one float ,but it still is awesome in the power department.

Cut the crosstalk, OK?

Stay on topic ("Which Holley is best?")

Be objective, helpful and respectful.

Otherwise...move on.

thanks
ron
ClubCobra Moderator

No doubt this is a carb from the days of quality coming out of a Holley box.Your carb isn't what i'm referring to.Things have changed.:(

I had Willy's Carb Shop dyno my Cobra when I bought it. Was disappointed with power it had and decided to build a new 351W...Called Willy with all the specs for my build and he recommended 4150 Holly..I bought a 650 DP, mech secondarys, manual choke(4777 series). Willy said out of the box this is the best bet and if I was not happy with it he could "set it up" and get some more HP...that is probably the route I will go.

It would be difficult to get a better performance/collar ratio than a new, out-of-box Holly 750 of the newest HP series. Choosing between mechanical (DP) or vacuum secondaries is simply a matter of personal choice, given that you are not racing. It is a feeling thing, rather than a speed thing.

i would suggest a 750 HP because you might make improvements in the future and might want the higher flow; say a new set of 304X FORD heads, or something. The above poster was correct about the original 715 cpfloat Holley for the 289 did work very well, both on the street and in racing.

The DP might require slight throttle feathering at the lowest rpm and WOT at low rpm might not be perfectly smooth. But, it will not be bad, since that is the specific correction that the newer HP series designs address. You might not even feel it, they are so newly sensitive to changes in airflow. The older Holleys did not really have a good fuel/air ratio control response at WOT and low rpm, because the slow moving mass air flow did not "suck" enough fuel into the airstream past the venturi because of old design airflow errors and not enough sensitivity at such slow velocities. Of course, the old designs were mostly fixable by good carb techies of the day for a cost.

But, when Demon really started to eat into Holley, the Holley R & D got hot and fixed what had been seemingly centuries old design flaws at WOT. Who of us did not have their carb go lean at WOT and low rpm when we used mech. secondaries on the street, especially?

The recent HP series corrects this and lots of other smaller but important effects, right out of the box.

Hard to recommend anything else to a non-techie, without taking a risk. But, good friends have also used the Demon and they recommend them. i have one on a rather hot FE from KC via our good friend Cracker, but have not yet run it, so i cannot say. But, it is a race engine anyway and the experience might not be at all useful.

I have had good luck with the Proform DP. Great quality and it was on the money right out of the box. Keeps the right AFR from off-idle to WOT (proven using wide band O2 from LM-1). Plus it looks just like the Holley HP.

I have heard good things about Quick Fuel on other sites.....and I think they use Proform parts.

Bought a Speed Demon with mech secondaries.

Metal shavings all over the insides. Cleaned it from top to bottom.

Re-jetted it and put her on.

Ran super with a little bit of tuning. Big dif from the Ed carb.

Thanks for the help.

I have a holley 950 HP DP. Seems to be pretty good. Although, I got the engine back fro the builder, and he cracked an ear on the base plate/throttle body. I think the bolt ears maybe a little weak, but he sent me a new throttle body/plate.

If you are going to get a holley, I like the HP series. More money, but I think a better carb with better parts.

If you go with a holley like carb, definitely get downleg boosters. I think they meter better at low throttle than a straight booster. I've heard good things about Braswell, although I'm not familiar with their cost. There were a couple other manufacturers I have always heard good things about, BG/Demon is not one of them.

If you have a stick tranny, given the choice, get a double pumper. If you run an auto, then a vac secondary would be fine.

670 st avenger on my 289 built to 350hp