600 eddy squirter question

I have a 318 with a 600 edelbrock 1406 carb and no matter how I change the jets and metering rods it always burns rich at idle. So I was just wondering, does anyone know, if I change the squirter size will it help lean it out a little at idle? and if so would it lean it out during cruise speeds? cause it seems to do good well cruising although it does burn pretty rich when I floor it (I see a little black smoke out back). dont know if it will matter much but my 318 has Keith Black pistons with about 9.5:1 compression, 360 heads, and the comp 275 DEH cam, and an edelbrock RPM intake. Thanks for any help, and or suggestions! -Kory