ok l just got this carb, used. l took it apart and cleaned everything. put it back together and put it on my sbc 350.it started right up and everything. only thing is, it runs rich, while at idle, and driving im sure. i've messed with the idle mixture screws that did not help the fuel richness. is it the floats? they seemed ok when l cleaned them and the moved freely. l once bent the float in my q jet to make it run a little richer. could l bend them to make it run a little leaner? what are the vacuum ports on the front? l heard one was a high vacuum and one was a low vacuum. what should l do? and for a basically stock motor, has 305 heads, headers, dual exhaust. what size jets should l get for best performance? what size came in the 1406?

Here is the link for edelbrock owners manual..http://edelbrock.com/automotive_new/mc/carbs_acc/pdf/carb_owners_manual.pdf

Double check to ensure that u have a decent vacuum running to the carb - if u have a decent performance cam that produces weak vacuum, the first thing u will notice is that you're uncovering the transition slots at idle, which means you're off the idle circuit, & flooding fuel into the carb. Watch it at idle - those throttle blades should not be uncovering that slot, & if they do, u may have to drill bleed holes through ur throttle blades if u can not adjust that any further back. Make sure u check that (plus the possibility of any vacuum leaks) before u start changing the jets. It should be jetted fairly okay for a 350 stock.

The previous post was wise to put up the reference to the Edelbrock carb - l was referencing that a million times with my 1406. The two ports on the front r not high/low - one is ported vacuum.

to adjust the air fuel ratio above idle u must change the metering rods or the springs under the rods. these carbs have fixed jet sizes & different size metering rods for richer or leaner mixture & different spring rates to change how much vacuum is needed to hold the metering rods in the lean position when vacuum is lost the rods move up & open up a larger hole for fuel to flow through thus making a richer mixture. try getting a spring kit from napa or oreillys & put in a softer spring this will give u better fuel mileage. since it was used someone might havechanged the rods too, find out what rods came with the carb from the factory see if that is what is in yours. these carbs r easily tuned for better performance & power both.

To adjust the floats u bend the float arms.

The 3 biggest & most common prob with the edelbrock carbs r the floats not adjusted right, too much fuel pressure, accel pump tuning.

Set floats with them hooked to air horn & gassket in place, sitting turned up side down at the tip of float needs to be 7/16'' from tip of float bottom to top of gasket.

Holding air horn in air right side up & floats hanging down, that needs to be 15/16'' to 1'' from tip of float to gasket

Now check ur fuel pressure. These carbs trys to flood at more than 5.5 psi. l use an adjustable reg & keep mine at 5.25 psi

check ur pump shot, for ur 305 u may need to put the linkage in the bottom hole or middle hole

These carbs DO NOThave ''fixed'' jets as the one person said. They have removeable & changeble jets ( l know, cause l had to jet WAY up on my 500 HP engine)

They do use metering rods & step up springs & u do use those for most mild tuning though.

The vac ports on carb front
pass side little = timed or ported vac (no vac at idle)
center large = full intake vac (common PCV valve hook up)
driver side little = full intake vac