During our physical comparison, we also explored the different types of installation hardware, such as the throttle- and air-conditioning-compressor brackets that each casting accepted. We learned that the Holley manifold uses only the throttle bracket found on Pontiacs from '75 forward. The Edelbrock castings, however, are designed to accept a '72-'74 throttle bracket, while the later bracket can be used if combined with the Edelbrock-supplied adapter. All the subject manifolds utilize the standard rear A/C bracket found on all Pontiacs from '73 forward. Since the various castings accept a few types of chokes, converting the Quadrajet to an electric choke coil may be a better option to minimize installation issues if a choke is desired.