You probably need to use some sort of thermal isolator as well. Edelbrock has a "gasket style" pad thats about 5/16 - 3/8 thick that fits the carb (not the manifold) and could be inserted into the stack.

Try to locate and use the carb lever hole that makes the primary travel about the same as the original carb when you depress the gas pedal. Speedway also has some bits and pieces that will allow putting a new carb link and ball stud together.  

Also try to end up with as few protruding sharp edges as possible down through the throttle bores - a smooth passage into the manifold. 

 
 Steve Metzger       Tucson, Arizona