Edelbrocks meter the fuel for the engine as required. They do it by the vacum for the motor. There is theoretically no too big of a cfm edelbrock it is all based on jet size. Unlike a holley you can take an 850 cfm Edelbrock jet it down and it will run as well as if you had a smaller carb. One of the things you are not looking at is the carburetors are set from the factory at a specific altitiude, as your altitude increases the air to fuel mixture leans out. The density of the air is greater at sea level. So 90% of the time Edelbrocks always run rich out of the box. Check your springs are not too weak/ strong for your rods. An easy way to do this is to pull your air cleaner off and start your motor, then you will see two little plates above the metering rods/pistons, then loosen the torx screw up and move the cover plate out of the way (dont take it off you might drop it and that could be catastrophic). You should see the piston and rod sucked down to the bottom of the bore,(if it is not you have too strong of springs in there and that is probably your problem) slowly increase the rpm of the motor, as the rpms increase the vacum decreases on the pistons and the height of the needles push up. Now you dont have to increase the rpm too much, if you are going above 1500-2000 rpms and the rods have not moved you have too weak of springs and you need to put stronger springs in. (be careful when you slide the plate out of the way if the springs are too strong the piston might pop out, also that is why you want the engine running otherwise they would just pop out when the plate is removed, oh and technically since the springs are matched you only have to do one side unless you want to check the spring is not stuck) After that it is needle and jet selection, and those are easy to change. One of the things about Carters/Edelbrocks ect is they are affected by vacum problems more readliy than Holley carbs so if you have a vacum leak somewhere then your carb will be affected by it more than a holley will.
Oh and so you know I run a 625 cfm Carter AFB and I dont have any problems with it. The motor is a very mild motor. It is an 87 5.0 HO with a aluminum ford 4V intake(until I can afford to buy a performer) on the stock exhaust manifolds an Accell street performance distributor and MSD 6AL box.
If you mean me and I assume you do then I am in Huntersville NC which is about 10 miles north of Charlotte off of I77 exit 18. I have not posted much here since I don't own a Maverick anymore. I sold them to members on here. I am looking at a one owner 71 or 72 that I am going to buy as soon as I can afford it and the wife says I can afford it. It is a retired teachers car that she drive to school for 25 or so years and parked in the field behind the house when she quit driving. It is very straight but has some rust from sitting in the field. I never got any good at tuning an Edelbrock but can tune my own Holley's pretty well. The Holley 750 on the 460 in my 71 F100 is still a bit rich. I am thinking of putting the 1850-600 back on there though as it is a lot more crisp. The 750 is a 3310 model clint
