not sure if this should be in "racing" or "engine", so here it goes:

I am looking for opinions from anyone who has used a demon 4 barrel, pro's and cons, everything you can tell me.

I am asking because since the engine is at the shop, the machinist is reccomending a demon because they are supposed to be much more tuneable than the holley 390 I am currently using (please, no ripping on the holley here, I have already heard it on all the other posts).

does the demon have the same mounting hole pattern as the regular holley 4 barrel?

I am going to be running clifford headers and intake, clifford cam (.498/.531 lift) compression is going to be near 11 to 1. head has had a full port and polish and oversized valves.

so does anyone here have experience with them?

Yep took a 750 Holley double pumper off my 65 Baracuda 340 and put a 750 street Demon on it all i had to do is set the idle. But i would like to know a little more about your engine because what you describe it could use more carb than a 390 cfm. My race engine has less compression but it has a ported head and i use a Holly double pumper lets say is over 700 cfm. Most people that doint like Holly carbs do not know how to rebuild them or tune them witch can be tricky. But when you nail a double pumper thats right all hell brakes loose. Why do think most all racers use them that runs gas. The bolt pattern is the same as a Holly 4150 . Thanks Ron Parker




New Year New Gear

Everything I have heard about Demon carbs has not been as glowing as Ron. They are notorious for being full of trash, and having many QC problems. If I were to try one I would definitely disassemble it and look for metal chips.

I have run a 390 Holley for years. Yes, they have their quirks, but I have tested back to back against a 500 Edelbrock and a 600 vacuum sec. Holley and it was faster than both.

I have nothing against Carter carbs, but people who tell you how great they are have never had a real race car.

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Official Cookie and Mater Tormentor.

Bagel is right Demon has had some isues. If i was going to buy a new carb i would buy a Holley double pumper for the street or a Holley Racing carb for the strip. The first thing i bought after putting a Holley caeb on my car was a complete manual from Holley for a 4150 carb. You have to know how it works unless you have got a Holley carb man that can do it for you. Thanks Ron Parker








New Year New Gear

I really don't like carters either........or edlebrocks.......I didn't think the holley was too bad of a carb, I was just looking for opinions since another gearhead recommended it.

Have you seen garbage in the demons then slantzilla? I want to know everything you can tell me.

What else did you want to know about my engine ron?

maybe I just needed to clarify, I should have worded it better in my first post:

I was running the holley 390 before the new engine mods; the new mods being higher compression and lots of head work and cam. The holley has only seen a clifford intake and headers, thats it. So I was looking for opinions on the demon unit since it was suggested to me, I didn't have the cfm in mind yet. Just looking for a quality comparison.

Holleys are perfect for the drag strip but are iffy to tune for the street. We have been trying to get the 750 double pumper on my buddys Nova tuned right and it is still spitting back through the carburetor and has numerous flat spots.

If you floor it though, it smooths right out and hauls some serious ass. It will pull the front wheels off the ground with a set of 10 inch slicks on the back.

I have always liked Carters because of their simplicity and good street manners. Very easy to tune. Most of my dislike of Holleys stems from the piece of crap Holley 1945 1-barrel.

You can't beat a double pumper Holley at the strip though. I have done found that out.

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82 D150-225/727
02 Dakota-3.9/5 speed
87 GMC C7000-8.2 Detroit Diesel/5+2

Threads about Demon carbs pop up on Moparts about once a month. Main complaint is trash in them, second being unfinished passages, with crap customer service being third.

Summit quit selling Demon carbs because of the quality issues. From what I've seen Barry Grant fuel system products in general are a crap shoot.

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Official Cookie and Mater Tormentor.

Bingo Bagel go straight to the Holley Carbs. Double pumper or racing carbs. Trust me on this. I would not put a demon on my race car but i know all about Holley carbs. And i will bet anybody out there. Who invented the 4150 Holley double pumper carb a free steak supper and a bottle of there favorite beverage . But if you louse you owe Rob Simmons a cool contributation. PS it was not Holley Thanks Ron Parker






New Year New Gear

so everyone recommends the 390 or should I go bigger?

I personally like the 390. I have been ungodly fast with one.

The only reason I am going to a 600DP on mine this year is that I am trying to run consistently in the 11's. I will let you know how that works soon.

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Official Cookie and Mater Tormentor.

did you have to use a double pumper? don't they make the singles anymore? or am I just imagining that?

what made you choose that carb?

You might wanna look into the 450cfm Holley from summit. It doesn't
have pcv provisions and is chokeless, but it's under $200
Just a suggestion and my .02....

thats a possibility.......


where'd slantzilla go?

I have been out at MATS winning Street Class with my rental car. I am home now.

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Official Cookie and Mater Tormentor.

so what made you use the dumble pumper then?