My car now has the Edelbrock Weber 8867 on it now. After helping a friend out he gave me his Holley 600, along with the rebuild kit(decided he didnt want it) I have a 400 in my car. I do want the Holley 750 but got other things to worry about first

Now what would be better, keep the edelbrock on or put the 600 on the car. I got a friend whos very very good with them and will help me through the process of installing.

1) use the brand carburator you or a friend likes to work on...whats 'best' is usually very personal taste
2) 750 imo is too big for a 400....650 Holley is fine on my 400...

using too big a carb is just wasteful...if you cant use all that gas, its going out the exhausts...the best is a carb that has the right air mixture...the leaner , the better mileage , but also leaner runs faster...too lean you will run hot though

on a 5L (Ford ) engine I had in a fiberglass car, I started out with a 650....car got 14-15 mpg and ws running ok...installed a smaller carb , car was faster and got 19 mpg...bigger isnt always better