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Im wondering how much torque and h.p. will increase on my 300-6 if i put a 4 bbl intake, 600cfm carb, and headers on. And would that possibly improve gas mileage? im gettin about 16 mpg now.
600 CFM is waaay too much carburator for the 300. You will never get enough RPM's to push that much air. A Holley 390 is the normal swap for a 4bbl. This will increase HP and torque. Mileage will increase if you stay out of the 2nd 2 barrels, but you know that won't happen.
600 is more carb than a 300 could ever make use of, in stock form.
However, the edelbrock 500 is a fairly popular carb to use on this engine. It's what I intend to use, should I ever make the jump from the stock carb. I don't really like holley carbs, even though they at least offer lower CFM ratings than 500.
I don't know what the gains are but I think putting a 390-450cfm 4 barrel will increase fuel economy as long as you stay out of it, as 4 barrels have smaller primaries, thus better gas mileage. I know they make intakes with square bore setup so you can run a 390cfm 4 barrel Autolite, which in my opinion is the best carb made. The problem with headers is they often times work outside of the normal operating range of most engines. If you can find a truck/rv header that would be more ideal, and long tube headers will give you worse economy vs. short tube. The other way to increase efficiency is change the camshaft, and if they have it a windage tray. Also setting it up for max vacuum helps when adjusting the carb. just my 2 cents
I don't know what the gains are but I think putting a 390-450cfm 4 barrel will increase fuel economy as long as you stay out of it, as 4 barrels have smaller primaries, thus better gas mileage. I know they make intakes with square bore setup so you can run a 390cfm 4 barrel Autolite, which in my opinion is the best carb made. The problem with headers is they often times work outside of the normal operating range of most engines. If you can find a truck/rv header that would be more ideal, and long tube headers will give you worse economy vs. short tube. The other way to increase efficiency is change the camshaft, and if they have it a windage tray. Also setting it up for max vacuum helps when adjusting the carb. just my 2 cents
yeah i like those 390 cfm autolites! And i am going to get short headers since it will give better performance. And ive already put a better cam in. and im constantly adjusting my 1 bbl carb to increase effiency. i seem to be getting the best mileage if i set the air/fuel mixture just right and run 91 octane.