Stromberg WWC carburetors
The following carburetor numbers originally used this length pump assembly:
Pump Bore/Cup Diameter: 5/8"
Instructions when replacing Stromberg accelerator pumps:
It is very important that the accelerator pump bore is completely smooth. Todays fuels with ethanol have less lubrication and demand super smooth pump bore surfaces. Polish pump bore with crocus cloth as required. Rough pump bore surfaces will cause pump cup to stick to bore and tear.
Do not allow carburetor cleaner come in contact with pump assembly.
Coat outer edges of pump cup with a light coating of grease, if pump bore is not submerged in fuel.
Long term vehicle storage:
If vehicle is dormant and fuel bowl is allowed to go dry, pump cup has a much higher chance of sticking to pump bore. If bowl has run dry, fill fuel bowl with fuel before pumping accelerator pump assembly.