650 dbl pump vs 600 VS carb

I want a decent carb for my 327 but am not to sure about the 650 dbl pump carb I have and how it would perform.. I have a stall converter th350 /327
bored 60 over performer PM intake combo so need a bit of advice on what you guys would use.. I also have a 750 VS carb but it acts up..
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On Wed, 25 Jul 2007 11:45:13 -0400, "chevrolet"

Even a 600 is a bit big for a 327 but if that is smallest option you have use it. With a 750 it would run poorly most of the time. Based on 90% efficency in induction (if you are lucky) you only need about 520 CFM at 6000 RPM with a bored 327. Smaller carbs give better low RPM responce and torque. A carb is one thing where bigger is not always better. ----------------- TheSnoMan.com
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I was thinking to put smaller jets in the 600 VS carb I have. I agree , it wastes gas to run that big.. If I could get a decent 550 carb, I would be happy but up here in shitholeville , not many hi performance stores.. I order from summit in the U.S
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found a new 500 cfm edelbrock.. would that be decent ?.. I also am running a 234/234 .488/4.88 lift cam.. thanx snoman..
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On Wed, 25 Jul 2007 15:01:31 -0400, "chevrolet"

WHat are you planning for you peak RPM (I am guess that cam should peak HP between 5000 and 5500 depending on intake). It you have no plans of taking past 6000 regularly I see not problem with a 500 CFM one on that engine. The reason you want to stay smaller is because you have a higher average velocity in venturi and better mixing and metering of gas which improves throttle responce and mid range torque. With a carb in a big heavy vehicle is it better to error a bit small than a bit big. BTW a 500CFM 4bbl is rated at 500 CFM at 1.5 inches of mecury in pressure drop across carb (about .75 PSI) so it can flow well beyond 500CFM with just a bit more drop. ----------------- TheSnoMan.com
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the cam I have is 2500-6500rpm I won't run it past 5500 as I would hate to miss it and hit 7k, and blow her up.. 327's like to rev ..and this thing even though bored 60 over picks revs up fast.
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oops.. forgot to add that the cam was 2500rpm-6500 and the intake is a performer RPM, headers,2.02 1.60 valves screw ins aluminum,stall was suppose to be 3000 on the th350 but feels like a 2500 .. bought it used so I was ging bhy what he said.. thanx again... I'l use the 600 (as I just had it rebuilt tonight) and if it gives me any issues with flooding etc.. I'l buy the 500 edelbrock.. Thanx for all the advice..
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On Thu, 26 Jul 2007 00:41:25 -0400, "chevrolet"

The reason it is stalling at about 2500 RPM is because the engine is not making enough torque to hit rated stall due engine build/cam. Knowing this I think I would suggest that you install a 3500 RPM stall or try advaning cam about 4 degrees as that will increase lower RPM responce. They make offset keys or a degree wheel. (retarding cam increases top end a bit) Smaller 500CFM carb would help too. BTW, 6500 is no big deal for a 327 but I would consider a RPM limiter set as 6500 or a bit less to keep it from overreving with that cam into valve float. ----------------- TheSnoMan.com
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wrote:

pump
/327
you
Is that right?? You should have told Chevy before they put the carb on the 67 thru 69 Z28's. They are only 302's.
Al
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pump
you
Big Al Your forgetting they also had crossram with two 4295 600 cfm holleys... 1200 cfm, a little over kill. But along with what snoman is saying most cars are over carbureted. 600 is about perfect for a 302 or 327. When younger and dumber I ran 850 dbl pumpers on everything. From my 165 hp factory 350 to my 600 + hp 454... same carb just rejetted. it ran like shit on the 350. With factory heads you'll never flow that much cfm, butterflies will be open but not that much air going thru. Also on the stall, it takes torque to stall a converter. On a stock engine a 3,500 will only stall 2,500- 2,800 give it more power you can bring it up to the 3,500. Worked on a race car that had vacuum advance that had a 3,500 stall, wouldn't stall past about 1,800 put a timing light on and set total advance to 38 with no vacuum advance and it stalled to 3,200 (engine didn't have enough power to stall to 3,500) What application are you using the 327 in ?
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