Appropriate Carburetor CFM for Stock 360?

[Kodachrome Wolf]

Howdy y'all.

I've been cruising the web and forum trying to get a decent idea what CFM rating carburetor would be appropriate for an '86 360 V8. While I've got a lot to do on my truck to get it driveable, I'm sure the current carburetor might give some grief given how long it sat with old fuel in it. Given the engine is entirely stock, I'd ballpark a 500 or 600 CFM replacement sounds reasonable in my factoring, but if anyone has a more appropriate recommendation, I'd honestly love to know to make the right choice.

 

[Different Drummer]

The engine is essentially a pump and is capable of pumping just so much air at any given RPM. Without calculating I would guess that at it's maximum RPM it will not pump more than what a 600 CFM Carb is capable of supplying. Certainly you will not be operating at that high an RPM very often and for any length of time.
A 500 CFM Carb would seem fine to me for a stock engine. But, I tend to lean on the conservative side of things.
I have a similar situation as yours. 350 SBC in a 1988 GMC. I use a spread bore Rochester ( yeah, the often maligned Rochester ) because of the small primaries. This Carb is more than I need at 750 CFM. However, it is an experiment in an attempt to get the best fuel mileage / drivability I gan get. I think if there was a spread bore Carb available to me at 500 CFM I would would be looking to give it a try.
Edit: what is the stock Carb? Research it's specifications. You could find a reputable rebuilder and use it.
Or, I think Edlebrock actually uses the original Chrysler design in their Carbs. I have not looked at them in years but I seem to recall they were designed like and looked like Chrysler Carbs. I believe they have a 500CFM Carb Available.

 

[Kodachrome Wolf]

Looking at my existing carburetor, it looks like a factory style Quadrajet unit. Informational available are saying those units could either be 750 or 850 CFM! Usually I’d err on the side of caution and lean towards the more conservative number as well, but if the factory rating is that high, I might try a similarly rated unit.

I have had some experience with Edelbrock carbs. The last one I used was a 500 CFM unit that went on a ‘56 265 SBC V8 due to a troublesome 4GC unit that was on there prior. It dialed in well and behaved well even in cold weather.

 

[Different Drummer]

Full disclosure, before buying my RAM I had ZERO experience with any Chrysler products other than working out of necessity on a slant six in a Tucker Sno-Cat.
I was thinking that the Edelbrock Carbs were the same as or very similar to the Carter Carbs. Likewise I thought that Carter Carbs were used on Chrysler products. Predominantly anyway.
Sounds like you might have a Rochester Q-jet which will be spread bore. However, I think the Carter Thermo-Quad was also spread bore. Maybe you have one of those.
I still lean heavily toward getting an accurate identification of the original Carb ( easy enough to do ) and having it rebuilt. Then again the Carb you have may in fact not be original having been replaced by someone else in the past. I would imagine some research on what was used in your vehicle's application could ferret out the information in those regards. Rebuilding would most likely be less than purchasing a new Carb and would result in using what the designers / engineers deemed best for your engine. Unless of course you are just intrigued by the idea of doing something different. Nothing wrong with that either.

 

[Kodachrome Wolf]

Yeah, this truck is somewhat unfamiliar territory for myself. After checking between the Carter and Rochester 4BBLs, it's definitely a Quadrajet on this truck. I'll see to it about cleaning this one first. I'm aware the $$$ you've gotta drop on a new carburetor, plus any extras one might need to get transmission linkages right and so on.

We'll see how it goes. I've got several other tasks ahead of that right now that I've got to address so I can test everything.