[halfstep]

Replacing gaskets, etc. (rebuild kit) on a carb thats not working right is not likely to cure it or push it into the performance window you want.
Search the internet and get your piece redone, flowed and blueprinted by a high quality carb shop. There are several all over the country.
They will take every detail about your engine, car and driving habits and for the same price ($250+) very likely get you where you want to go...and if it doesn't work out they will probably re-work it at nominal or no charge.
Too many people give up on one carb, buy another, and end up in the same or slightly better place and have no recourse for the tuning and adjustment necessary to get their carbs working well.
Give it to a professional and solve the problem.
My two cents.