Wrong parts?
What is your LIST # (eg 1850-1 stamped into the air horn / choke plate area) and what is the brand and part number of the kit or needle and seats that you have been supplied?
There are 2 different types of needle and seat assy's.
The original Holley type uses a seperate adjusting nut and screw, and some of the aftermarket replacements use a needle & seat with a slot cut into it to do the adjustment with and a much thicker lock-nut to secure it.
Holley Tech float adjustment instructions
I always like to start with a "dry" setting method, which will get you VERY close, followed by a "wet" sight plug inspection and minor adjustment.
Do you have a regulator and pressure guage that you are using with that electric pump, or are you assuming the pressure is "as advertised"?
HTH,
Don