hi guys so i have a 327 with a 600 cfm edelbrock carb on it is a old carb and needs a rebuild. this said i also just happen to have a brand new 750 cfm just sitting around that i have no use for will it be to much for the 327? it runs pretty good with the 600 but like i said the 600 is old and the 750 is brand new. what is the best choice. thanks i just repainted the engine and i have all new valve covers and air cleaner so i want to run good and look nice pic is "before" of engine bay will post "after" soon
Not a lot of info on the hole package but I would say you will loose throttle response, a**** other things......................
I would have to say no but you didnt post what cam or heads type of headers Etc. what jets are in the 750? also what cam on the pump side?
You would have to jet it way down for it to run good unless youre pushing some high HP #s. I would venture to say a 500-550cfm would prob find you a good 20 horse over that 600 on a close to stock engine.
Hi It will work okay. But unless you are turning 7,000 rpms and your motor is seriously built, IT WILL MAKE YOU SLOW. But, it will give you the good old bog sound that really means you are going slower than you should, not going faster. A stock 454 will turn a better time at the dragstrip with a 600cfm than a 750 cfm double pumper. Have fun either way. wil www.sakowskimotors.com p.s. lean the jets out if you are going to run it. You could even throttle stop it to keep from bogging like if you have 2 4 barrels on a stock 350 motor for looks. Over carburetion is only cool in songs, not at the track.
stock 327 with douple hump heads dont know alot about it i know it came out of a 65 el-camino i just bought the truck and the engine was just installed before i got it
I have run as much as 1320 cfm 2 660's on a 337 inch small block but it had a 663 lift 320 duration roller 617 gears in a 2800 lb car but if I were running a mild motor on the street I agree with syco620 kep the cfm under 650 that's not to say you can't run a 750 if you can't sell the 750 by all means run it I wouldn't drop the jet sizes to much because the venturi size remains the same and you run the risk of going lean hope this helps
im sure i can sell the 750 i was just thinking that i had it i should use it i think i will probley just rebuild the 600 and sell the 750
My first car was a 68 Camaro with a 327 .030 over, 202 heads and a Holley 650 double pumper. With the Muncie M22, she would just kick ****. Wouldn't have wanted any more carb than that though.
If your 327 was operating at 100% Volumetric Efficiency and was turnjing 8,000 RPM a 750 is perfect. Your VE is more likely around 80% and redline..... what? Maybe 5500 if you really push it? In that case you would need a little more than 415 cfm. You can jet the 750 down and make it "work" but in a PU your throttle response is going to ****. In all reality a 390 Holley would probably be just about perfect. The 475 Holley Truck Avenger would come real close to being a "bolt it on and go".
Its too much ,You can bolt it on and it will run ,But the idle mixture screws wont work and you will be running to rich at idle .There is a trick to solve this problem but I forget what it is ,My advice is to put a 670 holley on there ,Ive been there before .69 327 ,fulie heads and automatic with mild stall and 323 gears ,In a heavy 71 elcamino ........Thats what I did ,The 750 will work but if you let idle alot you will foul plugs ,
Some 327's came factory with 750's but your going to lose throttle response and gas milage. It will work but you might not like it.
Too much unless your gunna be turning high rpm and have a big cam ,worked heads ,headers ,etc.It will run better on the street and proly be faster with the 600 on a mild 327.I would think a 650 or 670 would be best though .Had a 750 Holley on a mild 327 once with junk heads and it was over carbed for the street IMO .It ran a bit better when i jetted it down and dialed in the powervalve size ,but was still too much IMO ...
I ran a 750 holly vac. secondary on a 327 .030, 194 heads, Edelbrock RPM cam and intake. All I had to do was take the check ball out of the vac. secondary. It ran like a scalded dog.
Listen to this guy ,he obviuosly knows what he is talking about.The biggest mistake people make IMO is too much carb.My 408 is running 11.40's with a 750 Demon .It all depends on Volumetric Efficiency (no getting around it).Its all about what rpm you intend to use it at ,plus whats been done to the motor.Its not a matter of this cubic inch motor should have this cfm of caburation on it in any giving scenerio.Its about what you trying to accomplish with the cubic inches you have...
will the truck is gona be my DD not trying to do anything crazy with it just want it to run good wouldent mind a little extra power
670 is perfect trust me ,Or a 650 ................600 will run ok but topend a 650 or 670 will work great ..... Also remember to buy a spring kit for the back va***n secondaries ,The stock one does not start opening till 5500 rpm. You get springs with the kit and I always put in the lightest ,That you will have to play with..........
If you want alittle extra power id try tuning the edelbrock alittle. Check your excelerater pump. There is 3 differnt holes on it to squirt more or less fuel. My 383 came to life when my buddy tuned mine in. The exhaust note even got louder. Im running a 600 carter pushing about 420hp 500ft.
You're referring to the L-79 327/350HP and it came with the 3310 780 ONLY because the Novas equipped with that engine were intended for NHRA Super Stock cl***es where they had to run the factory carbs and "stock spec" cams. It sure wasn't because it was the correct carb for them in stock form, they wanted the big carb for high RPM all out racing. That's also why the L-79 Hydraulic 350HP cam had such long advertised duration, for when they "blueprinted" the cams. If NHRA had used duration at .050" it would have been a whole different story, a "Super Stock" legal blueprinted stock spec cam was far from streetable OR stock! The '67 and '68 275HP 327's came with a 750cfm QuadraJet but that's something altogether different, a QuadraJet would be perfect for it. The 427/390 HP Big Block Impalas came with a 585cfm Holley and it was plenty of carb. They were intended to be used for towing not racing, as it turned out they made pretty good Stock cl*** drag cars too.
Your 600cfm Edelbrock is the sensible carb to run. Just because it is "old" does not mean it is broke. If a carb continues to get clean gasoline flowing through it, very little can go wrong. Old gas sitting in a carb for too long does more damage than anything else.
get a rebuild kit for the edelbrock. sometimes you can get away with taking the top off the edelbrock and just cleaning it out.
On the other hand, he's already got the carb. What would it take to stick it on and see what it runs like, a gasket? Geez guys, all this technical formula stuff gets old. By the way, that carb only flows 750 at a certain negative pressure. I've used 750 dbl pumpers on 283's, 327's, and 350's. The 283 complained a little bit. Also, the 302 came with a vacuum secondary 775 cfm Holley dual line. Come on dude, put it on there and report back to us. This could very well be an eye opening scientific experiment, or not.
If you want a little extra hp and throttle response, wire a toggle switch to the coil and run the timing at 55 to 60 degrees advanced. The toggle switch is so you can shut the spark off until you get it turning over. 750cfm is too much carb for a mild small block
If you run the timing that far advanced your trying to compress a already exploded combustion chamber mixture! In other words the mixture is ignited & wanting to expand, hence have a downward motion & the piston is still traveling up, it is in theory "flexing" the connecting rods having a "whip" effect. But it doesn't take too much to break a rod. The purpose of timing is that the spark plug fires at the time it'll take the piston to be at TDC, so i guess at idle its 7 or so degrees ,faster (less time) it fires at 35o or so because of the speed & the shortime it has to travel to TDC so what you are stating is actually doing alot of harm & not a solution to a carb thats too big. You can only fit so much CFM into 350 cu.ins!! Thats it in a nutshell guys, simple combustion engines 101" jimv
No **** **** Tracy. I didn't say it may not have ill effects. However, I ran a '66 flat top 327 that way for 2 years. The motor only ever knew two throttle positions. Shut off and WFO. I suppose you think the rope strung through the firewall to ****pit I used to run the secondaries on the 650 dbl pumper was dangerous too? We were broke ***ed kids, anything for an extra pony or too It was still running fine when I pulled the motor and sold the car.
I'd bolt it on and see if it works, you probably won't be able to tell the difference without a stopwatch. A vacuum secondary carb doesn't flow 750 CFM unless it needs 750 CFM. And as far as jetting it down, you change mixture with jets not CFM. Larry T
Except hard water... don't know how it got in there but I bought a 750 Bonneville years ago that had sat with water in the carbs. Picture an old faucet that the minerals in the water had been eating on, that's what those carbs looked like inside. I got 'em to work good enough to run until I could get it sold. I told the buyer up front, he had a wrecked parts bike with good carbs so it was no problem for him. He put the carbs on and promptly wrecked that one too a week later.
O.K. , Here is my 1st hand experience with this same situation. In the early 80s I had a 34 Pickup with a 1967 Nova 327-350 H.P., factory L-79. I now wish I did not let the motor go with the truck when I sold it !! The trans was a 350 Turbo. It had a 12 bolt rear with 3.08 gears. I started with a new, right out of the box, Holley 750 va***m secondarys. The truck ran and idled O.K., but not sounding as "crisp" as I thought it should. It got about 16 MPG on the highway. I then bought a new Holley 1850-3 (600 cfm va***m secondarys). It idled and ran a lot cleaner and had a crisper exhaust note also. The highway gas mileage jumped to 18 MPG. So, the Moral of the story..The 750 will work, just not as good as a 600. I personally would buy an AFB kit online for about 20 bucks and rebuild the 600. The AFB carb is VERY simple. Good Luck !!
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