i need to get beter fuel millage out of a chevy small block 305 stock
 

i have a stock small block 305 with a 600 cfm edelbrock carb i need help trying to figure out how to get better4 feul millage the most i can get is 11.5 miles to a gallon which i have been told by others is 1.5 miles more then a 305 should get if any one has any idea's or can help let me know

First off, is a adapter plate in use? Next how many miles are on it?
Third what is the timing set at.
What vehicle is it in and what is the rear gear ratio?

Put the two barrel that the factory put on these engines. Get a vacuum gage and train your foot to follow what the gauge says. This thing in a van?

In my opinion, the first step when you're trying to improve mpg is to make sure you're calculating mpg correctly:

---verify that the odometer is tracking miles correctly. One way is to match it with highway markers.

---fillup at the same station AND and the same pump if possible. Fillup until it clicks Then divide miles driven by gallons you just pumped.
Example: 300 miles/10 gallons.

First, it's NOT stock, since you don't have the stock carb. Second, you didn't tell us the year or model. If this is a mid-80 305 that originally had the computer controlled Q-jet, a LOT needs to be done to convert to non-computer operation with good mileage. Third, if this is in a heavy vehicle, you won't get much better mileage with any engine. Give us a little more info to work with.

a 2v intake and carb, high performance ignition, free flow intake filter, new cat converter, headers, properly inflated tires, port work on exhaust, synthetic fluids..... all i could think of lol :P

Except what vehicle it's in.

try 7 mpg....HIGHWAY!!!

You forgot the EGG!!!
Drive like you've got an egg under the gas pedal!!!

X2 :thumbup: driving habits are the biggest thing when it comes to mileage.
Also condition of tune, plugs and timing, very critical
The carb, meh ... put a well tuned Small quadrajet non electronic carb on it.
Be sure you have a non computer distributor on it.

Your mileage will go up.some.
How many miles was a good question, a good tune cant help an engine with excess blow buy at the rings. To much is lost right there.
Need to do some preliminary checking on the situation. Dont just throw parts at it . Learn how to ID a problem and how to do basic tune up work.
Check it out first.
What kind of distributor does it have? Does the engine smoke?Does it have plenty of power as it is right now?

What tranny? Best thing you could do to improve mileage is an overdrive tranny. If it's a 3 speed auto, then find a 700R4 or 2004R and instll it. You'll get much better mileage on the highway.

Milage.........
 

What is the rear end ratio?? will have a LOT to do with milage.... :)