I am having carb issues and I need to just replace it. It is old and worn out. I have found a new in the box Edelbrock 600 for a good price (square bore). Would this be enough carb for a bone stock 460 that is used maybe 1000 miles a year mostly to tow and haul crap?

 

If I'm not mistaken, the factory Holley 4180 was 650cfm. Considering the price and your lightweight application, I'd use it.

 

A few years back, a buddy of mine had an edelbrock 600 on warmed up 460, stuffed into a crew cab dually. He didn't care for edelbrock carbs, but couldn't complain about the way it ran, or the 10 MPG average he got while towing heavy loads.

 

Great, thanks. I may just go get it.

 

I don't recommend a 600 CFM carb or an Edelbrock. Edelbrock leaves power on the table and (in my opinion) are more complex and difficult to tune than a Holley. 600 CFM is just too small and will leave power on the table. You should be looking about 750 CFM for a stock to mild 460.

For comparison sake, I've run a 600 CFM and a 750 CFM on the mild 460 in my truck and the difference was night and day. At the end of a day for a carb you're talking peanuts and little price different between 600-850 CFM so just size it properly.

 

The stock 4180 Holley is a 600 CFM. I run a 4160 600 CFM on my 460. If your towing the 600 works out the best.

Craig

 

Unless you plan to visit the 4500+ RPM range often, the 600 will give better throttle response, and works rather well in the low-mid range RPM that is used most of the time, especially on a stock or near stock engine.
It's true that the 460 likes a bigger carb for higher RPM, particularly one that has been built for more power. But for an everyday driver, the 600 is fine. A stock/near stock 460 doesn't exceed 600 CFM until somewhere around 5000 RPM. With the current trend in gas prices, most people aren't going to running that high RPM on a daily driver.....

 

Funny you say that, because for me towing a 5000 lbs trailer with my 6000 lbs truck the 750 made a noticeable improvement.


Difference in throttle response should be negligible, this isn't a small block we're talking about. 750 CFM is a relatively small carb for a 460 but suits a stock-mild engine well. Since cost is similar for a 600-850 CFM carb it only makes sense to size the carb best for the engine. FWIW I daily drive mine with a 750 CFM double pumper and it rarely sees over 2000 RPM unless I'm towing. The improvement down low was noticeable over the 600 CFM 4160 I had on there previously.

 

I had a Edelbrock 600 CFM on my motorhome's 460, it was woefully under fueled with it on there to the point of backfiring through the carb and not wanting to go up hills.

I even went so far as to change the metering rods and springs to what an Edelbrock support tech suggested. Did not help at all. Might have worked had I changed the jets, but I didn't try. I just went back to the holley after I found a replacement primary bowl (original fuel inlet had been stripped enough to leak all the time.)

Comparing CFM between Eddies' and Holley's isn't going to cut it. The characteristics of each carbs venturii are different.