I'm getting ready to build my first engine. I currently have a brand new Edelbrock 600cfm performer on an olds 350 rocket. I'm going to be adding a 455 big block. What carburator should i have or would the one I currently have work just fine?

 

What kind of engine are your building? Street, Street/Strip, Full race, etc? For a street driver, a well tuned quadrajet will give decent mileage (as long as the leadfooting is minimal) in routine use and has those big secondaries for showing off. For other applications, aftermarket carbs may be better.

 

I'll just be building for street performance. I was told an Edelbrock 650cfm or a 750cfm would also work. Is that the case?

 

You can always reduce the jet size if they are to much for the engine.

 

You should move up to at 750 CFM carb. A quadrajet or a Holley are both good choices. I find the Holly easier to work with myself and run a 770 CFM avenger on my 455. This question always creates controversy with a number of different opinions.

 

I've been told by numerous people the Edelbrocks were the simplest to take out of the box, and run.
So I put one on my 70 442 clone and it's runs fantastic. I just have to tweak my idle circuit a bit.

http://www.edelbrock.com/automotive_.../thunder.shtml

However, I know alot of guys here like Q-jets.

 

The manufacturer/design has little to do with the power output in given application. The size (CFM) has everything to do with it.

Rule of thumb: Smaller carb = less power and crisp throttle response vs larger carb = more power and "mushy" throttle response.

If you have a "square bore" manifold, a (vacuum secondary) Holley or an AFB/Edelbrock will work fine. But, it if is a "spread bore" manifold, a Q-Jet would be your logical choice.

You can use this calculator to find best size for your application.

Norm

 

In my experience most people tend to err on the side of over-carburetiing an engine. The 'if a little is good then a lot must be better' philosophy really doesn't hold true with carburetors.

I have a mildly built 390 big block Ford motor in my truck. I run an Edelbrock 600CFM carb on it and it runs great.

Edelbrock makes a good carburetor. They do have a reputation for being pretty good "out of the box" although I think Holley is trying to combat that a little with their newer line of carbs. I recently installed one of the Holleys that is supposed to be ready to 'bolt on and go' on a customer vehicle. Outside of there being metal debris holding the float open which I had to repair beofre I even was able to run the car for more than 10 seconds it turned out to be pretty good. Personally I guess I would go with the Edelbrock over the Holley just based on what I've run.

Actually if it were me I would pick up a Q-Jet. They are designed to give thousands of trouble free miles and are a great combination of performance and economy. I think Summit is even selling rebuilt models now for specific performance levels. I'd check that out.

Jay

 

Thousands of different answers/opinions to this question as Citcapp said. From my experience, I love the Edelbrock. 600 CFM is too small for your 455. I'm using the 600 on my 350 and am using the largest jets and the narrowest metering rods.
Another calculator (simpler to follow) http://www.carburetion.com/calc.asp

 

All of these units will perform very well.
The quadrajet has smaller primaries that will help with economy, and large secondaries that will give good power. Most are 735 cfm, some late ones, 800 cfm.
The Edelbrock (redesigned Carter AFB) will usually bolt on to anything and run really good, without messing with it, as long as it gets clean filtered fuel. Go to the 750 for your 455.
The Holley 4150/4160 series will give great power. They have several more designs over the years, one which Summit sells, and others swear by. Stay away from older q-jet replacements, IMO. I could never get the fuel economy with Holley's that others gave...you can get these in almost any size.

I doubt if fuel will ever get less expensive,
Your wallet may have to decide.
My opinion
Jim

 

I've got my Edelbrock 750 on order! Thank you everyone for your input. Next question, what brand pistons would be the best recommendation, Speed Pro, Federal Mogul, Keith Black or what?

 

You will be happy with the new Edelbrock you ordered. Just make sure you set the idle mixture screws, idle speed setting, and choke properly.

FWIW, I used the TRW L2323F pistons in my 455.