take the line off of the fuel pump coming from the tank and blow air thru it into the tank, then put a new filter on and clean the bowl in the carb. the new pump has awoken the dirt devils in your fuel tank.
same thing happened to mine, had to clean out the tank and replace the rubber hoses under the cab.


http://www.flickr.com/photos/11977495@N06/sets/
1952 COE
1952 3100
1953 3100
1950 6400
1951 Suburban