[Green Machine]

Best place for me is right here on the parts board. I have purchased 2 1406 carbs with electric chokes from the parts board here. Both were low miles/age and had not been messed with. You will want to download a manual from Edelbrock's web site and verify float level and jetting. I'd check the float even on a new one as several have commented the even the new ones can have misadjusted floats, maybe from shipping.

I saved a ton of money buying from here, and when I need another one I'll check here first. The 1406 is the most popular model and easiest to find. The 600 cfm models will not be too big for your 307. I run a 650 cfm Holley on our 68 307, and a 600 cfm 1406 on our 305. As soon as I can get a new intake for the 307, it is getting a used 1406 also.