ok guys ive talked to a numer of my friend and im hearing everythig from a qJet to a demon 750 . i wanna know what you guys think.
Heres the stats (what i know ) for the motor
350 .30 over
270 duration cam
stock 882 casting heads with some kinda valve work
edelbrock performer RPM intake
Edelbrock 600 CFM elec choke carb
TRW Forged pistons and forged rods
CR ~9.7:1

the car has gone 14.3 with te current carb on it. i know i can get it lower if i learn how to drive it, but i think the carb is killin it up top, and i think it also needs to be rebuilt. But im not SBC or Carb expert. This is a daily driver during the summer so keepin it in double digits for gas milage would be a plus. SO somethgin that would be decent on gas but give a big kick in the *** when i hit the thottle. im open to any and all sugestions cept for FI right now.

 

You need to figure out what kinda horsepower you are pushing, that is the best way to figure out what carb you nee i think the recomend the 650/670 up to about 300/350 hp, go with one of the good out of the box carbs less tuning for you i.e Road demon, Edelbrock and so on. Hope this helps!!

 

Holley 670 CFM Street Avenger should be perfect.

 

Doesn't matter what kind of valve work. Those heads are terrible. Therefore, with the Edelbrock, you've got a good combo.

That's the defination of a q-jet.

 

I dont agree with that at all. With the proper tuning, an edelbrock is a good performance carb. People are just under the impression that they are bolt on replacements. They require the same amount of tuning as a holley. True, they will never be a DP style carb, but they still perform well.

 

I was referring to the 600 CFM vs. the proposed 750 CFM. Guess it didn't come out right.

As is often the case, improvement is expected with a carb change, when it isn't the carb that's holding it back.

 

You're right five7, after re-reading it, I misunderstood what was said. We edelbrock guys are like the bastard children of all Carb people.

 

I calculated the requirement for a 355 & 600 CFM on another thread. With 100% VE, a 600 will handle a 355 to 5800 RPMs.

However, the 882's won't flow enough to use all of the 600 CFMs at that RPM level.

 

Formulas are useful for learning what should work, not what does work. Barry Grant did an interview a couple of years ago and listed what carb he KNOWS works best and they were all larger than the calculated size because there is much more to it than CID, RPM and VE.

You don't have to believe me, that's just the way it is, I know from years of drag racing experience backed up by probably the most knowledgable person you can find on carbs.

 

.......you forgot "red headed step child"

With a dual plane intake "over carbing" would not hurt performance, as 5.7 said, the heads are the bottle neck, the carb wouldn`t be my 1st worry. The edelbrock is a decent carb but holley based carbs are in my opinion easier to tune and parts are easier to obtain, I think autozone even has holley parts. I don`t see a lot of cars at the strip using carter based carbs, at least none that are crazy fast. I`d stick with the eldey and get some heads, but if gotta get a carb I would suggest the holley 4150 vacuam 600 or the demon 625VS, either would be more than enough

 

With a manual tranny, and/or regular drag racing use, a double pumper would be the better choice.

A 350 with a dual plane intake can easily handle 700-750 CFM.

FWIW, I am fully aware of the difference between theoretical formulas and real world experience. I happen to have found the Holley recommendations very good for "little guy" real world results. I don't recall seeing the BG interview, but I know they are heavy into maxed out racing packages - not exactly what we're dealing with here.

 

I see it just the other way, but thats because I have been using these carbs all my life. As for the racetrack I see quite a few guys running carter/edelbrock carbs. You just see more guys running holley based carbs. I think a lot of that has to do with the advertising and the mentality of "if it aint a double pumper, it aint fast".

I would leave it at, the edelbrock will perform as well as any vacuum secondary carb, but if you need mechanical secondary performance, get the holley.