my 600 cfm electric choke preformer was plug and play,installed on a stock 74 302. just adj the idle mix screws. been on for 10 yrs with no teardown.there was a small amt of fab to get the throttle and kickdown just right.
If your engine is just like the one that they configured the carb for out of the box then it is plug and play. It is most likely not but it could be close enough to not make much difference.
I ran an Edelbrock 750 on my mustang and I had to re-jet it and change the needles. The step up needles are very easy to change. Jets require you to pop the lid off and you need the tuning kit.
If it is a brand new carb I would take it apart and clean it. They sometimes have bits of machining junk inside. The Carter design is very susceptible to dirt and trash so make sure you have a good fuel filter.
After note: I sold my beloved Edelbrock 750 and bought a Holley 650 double pumper for the mustang. The only reason was that my current engine makes 7 or 8 pounds vacuum idling in gear. The Edelbrock couldn't deal with it. I had to have a 4 corner idle system. The old carb also did not have an adjustment for when the secondaries come in. I'm not sure if they have changed that now or not. You could very carefully shave some weight off the pivot but it was iffy at best.
Think there best on stock motors. Ever wounder why nobody copies there configuration? Right now possibly the easiest to tune are the Quick Fuel street and street strip carbs. Most of the metering orfaces are jetable.
My 600 cfm performer ran fine out of the box on my 302 but performance seemed to noticeably improve with the changing of jets and rods. Hope to run it on dyno soon to get an idea of how much it changed. You can download the carb manual from edelbrock's site. It gives a decent (but not entirely clear to me) procedure for selecting rod/jet combinations. You can buy a tuning kit that has some, but not all, jets and rods you might need. Didn't realize this until after I bought it and had to by additional ones separately and ended up not using the ones in the kit. The kit also includes different step up springs to adjust the metering rods for low vacuum conditions. Be careful about richening the primaries in cruise (metering rods down) mode. I did that on my first attempt and it took the mpg down to around 7. Richening the power (rod up) mode without richening the cruise mode kept the power improvement and brought the mpg back up. Also, in my case, the carb built up a lot of heat leading to fuel boiling (I think) and hot starting trouble. A wooden carb spacer helped a lot with this. Changing jets and rods is pretty easy but I don't think the carb has as much potential for adjustment/fine tuning as a holley style carb. You can basically go three steps richer or leaner from the factory settings
I have used edelbrock carbs in the past and was happy with them. Both were on a 455 pontiac motor with a comp xe274 cam and home ported heads. The last carb I used was the AVS800 cfm. The best run I got out of the car (a 68 lemans with T400 and 3.55 rear) with the 455 was 12.45 with a slow 1.88 60 ft. It was a street car that I raced a couple times a year. Got decent mileage for a big motor and was very responsive. I ran a 850 holley DP for a short time. Didnt go any faster and got terrible mileage.
I did a small amount of tuning on them. I got the tune kit and experimented till I found the best combo for the motor.