I have found myself trying to figure out what carb to go with. I spend more time at the track these days and will continue to hit all the nostalgia drag racing events, but I also drive my truck on the street quite a bit. I have a mild Chevy small block 400, runs 9.5 to 1 compression and the cam is 480 / 480 lift. I would like to shift around 6000 to 6500 when racing. By doing the math and depending on what rpm's I shift at, it looks like I will need a 750cfm or 800cfm carb to make things work the way I want them to. Now the question is which carb will give me the best of both worlds. Edelbrock, Holley, Proform or Demon? I have have always used Edelbrock on stock applications, but I can not find any reviews for performance or drag racing type applications. Any advice or personal experience would be appreciated. Thanks
i switched from an eddy 750 to a holley 750 and ran a couple tenths faster. i am sure everyone will agree holley can get you there faster. i love the edelbrocks too, they're great on the street and are low/no maintenance.
I dont think that little cam in a 400 is going to want to spin 6500 RPM , a 650 would be sufficient, double pumper if more track or the 670 vac. for more street
CHEVYRAT...my choice is edelbrock for sure, but don't know if they go up to 750 or 800cfm ? demon is probably the most expensive, but could well be the best!...POP.
I know it wasn't listed in your choices, but have you considered a quadrajet? The 1976~1980 will be mostly be 800 CFM (200 primary, variable 600 secondary). Armed with a copy of Cliff Ruggles book and some patience, you can obtain the same amount of power as with any of your choices, PLUS probably 10~20 percent BETTER fuel economy when street-driven. If you do the q-jet, make sure you use an intake designed for the q-jet. Don't try to use a square-bore intake with a spread-bore to square-bore adapter. And after you win at the track, the look on your competition's face when you show them the "quadrajunk" is absolutely priceless! Jon.
I'd reccommend a doublepumper, as you say 750-800cfm, tall single plane intake like a professional product hurricane, edelbrock victor, or a brodix. I've had good luck with demon, scared of holley right now and have been using proform/quick fuel carbs with great luck. Quick fuel is the better of the two but i think they'll cost more, been using the proform street carb, it has all the good features of a race carb and has electric choke for low cost. That's the one to jump on.
(hi Mark!) 4779 Holley - 750 double pumper for performance as long as the truck is light and its gear/converter combination is pretty close, but its fuel economy won't be worth a damn. A sorted out QJet would do fairly well in this application, and the fuel economy would be better. My AFB/AVS experience is more limited - so I cant offer much there.. (Don't carb application questions like this usually turn into a shitstorm? They do on some of the other boards I frequent...)
Thanks for the input. I do have a fear of Holly due to past experience, but have heard many good things about the quality of Proform and Demon.
Edelbrock is great for the street but not that great of a performer racing. The new holly street avenger is supposed to be a nice carb. Ive always wanted a demon but i aint forking over that kind of dough. As for the size, i would not go over 750 for street use. Smaller carb will be more responsive. I wouldnt go over a 650 with what you explained you have. To much carb could lower you ET's because it will bogg at the start.
As much as I hate to say it if I way in need of a good carb for drag racing only , I would go with a Holley ! I hate them for the street but a good choice for the track . Grants are a good carb for the street and are good on the track too . Edelbrock is my number 1 choice for the street ! Quadrajets are a very good carb if you know how to rebuild them correctly ! Will serve you well on the track too ! There are allot of very good carbs for street/race but you need to choose the one that works best for your set up . Just don't do what most people do and OVER CARB your engine ! RetroJim
I run a 600 cfm Edelbrock right now and it is under-carbed. Based on the math and test runs at the track, I need to step in to at least a 750 if I shift around 6k. The 600 is good for cruising, but not enough for the strip. Thanks for all the input.
I have always called the Holley, Edelbrock or Demon tech line ... you can go through all the details of the engine and they will advise what will work best ... it may sound to simple but it has worked for me.
My 408 Mopar has about the same cam as you Chevy (480 lift) ,and loves the 750 Speed Demon .Easy to tune and great with the sight windows in the bowls for the float level settings.They are great carbs for street / strip.Crisp throttle reponse off idle on my motor and is feeding it fine at 6000...
I've talked to the tech lines and they all say their carb is the best. I've been looking for some real world experiences from those who have actually tried different set ups. Can't afford to make the wrong choice. Hey Shocker - I've seen your car run and that makes feel better that you have a simular cam profile and the 750 Demon is working good for you. I am starting to lean toward the Demon over the Edelbrock. Catch you at the THAW.
For me the demon is the easiest. Use Holley jets. Glass sights for floats. Adjust floats like Holley. Can set final balance by removing carb/ breather stud and doing adjustment thru opening. You dont have to worry about power valves. Not great for economy, but good every where else.
I find the Edelbrock AFB's and AVS's easier to work on but the Holley is definitely better for peak HP. If you do go Holley, get a new one. Used Holley's are a nightmare to tune unless you ~really~ know what you're doing. BTW: Holley sells refurbs on ebay... http://tinyurl.com/yefz96r If Holley, consider the 750 vacuum secondary Model 3310. If Edelbrock, either the 750afb or 800avs would be great.
Would need to know more about the combination but you may also want to look at the 750 annular we offer. In a heavier vehicle it has real good throttle response and drivability. In regards to vacuum or mech secondaries we typically recommend vacuum for autos with the converter less then 3000 and the mechanical for auto with the converter 3000 and above as well as a stick car.
We run a Holley on the crical track and on the salt flats, Demon is good it just cost more Money. If you got try it if not Holley is the ways.. Holder to the wood and keeper straight..
Knowing rest of combo would help . For comparisons sake, I ran 403 Olds with 496/520 lift cam with differant carbs, the 650 double pumper produceing best results when I could keep my foot out of it street driving . 750 vac. work fine also . shifting was at 6000 cause thats all the motor wanted to do with that cam . I used open plenum intakes. The Holley vs Edelbrock, driving style and more street or strip . Ran them back to back 600cfm on a 330 same ET , edlebrock had better 60ft while holley gained 5mph on top end .
I run a 39 Chev truck. I have not had it across the scales, but I would guess no more than 2500 lbs. It's light. I run a 3500 stall in front of a built Turbo 350 with 3.73 gears. 67cc heads with 2.02 / 1.60, D-Stroked small block 400 with a dual plane intake. I hit a wall at 5000 rpm right now with the 600 Edelbrock. We tweeked the carb a bit and got to 5300 rpm before hitting the wall again. I can say I am satisfied off of the line, but not on the top end.
352 377 ? destroker should wind high either way . cam is small to crank much more rpm I think , add some 1.6 rockers if you dont want to tear into it . but I would go bigger on cam and definatly a single plane intake, weind 7546 was one of my favorites , vic jr also works well and are plentyful used .
this one would probably give you what you want http://www.lunatipower.com/Product.aspx?id=2326&gid=297
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