They are usually not needed and the prices for them are ridiculous.They were added to reduce the chance of the engine shutting off when you release the throttle too quickly, but you can fix that by increasing your idle speed about 50-100 rpm.
Rebuild Service for YOUR Stromberg Model 97, 48, 40 Carburetor. Reduced shipping
REBUILD SERVICE for YOUR Carter BBS Slant 6 Carburetor READ DESCRIPTION
2000-2004 FORD F150 ABS MODULE REBUILD REPAIR SERVICE TO YOUR UNIT ONLY
Ford F150 ABS Module Repair Rebuild Service 2000-2003 | Ship Your Unit Into us..
John Deere 2640 Injection Pump Rebuild Service !!Ship Us Your Pump AR67647
Rebuild of YOUR Nash & Corvair Carter YH Carburetors. any year, any style.