Compatibility is determined by the barrel configuration (Single, Progressive, or Synchronous) and the mounting flange dimensions. Ensure the supplier specifies the choke size, main jet, and air corrector sizes pre-installed in the unit. For specific engine types, verify the linkage type (mechanical or cable) and whether the unit features an electric, manual, or water-heated choke system. It is essential to confirm that the needle valve and seat are rated for the fuel pressure of your specific vehicle's fuel pump (typically 2.5 to 3.5 PSI for Weber systems).