You might be able to modify a later Holley solenoid bracket to work with an AFB. It attaches to the baseplate of a Holley carburetor. There might be enough metal to cut/ weld/ drill/ bend to attach to your front carb stud. The Holley part numbers are 20-9 for the bracket, 46-74 for the solenoid, and 26-57 for the big attaching nut.
A '69 factory Rochester bracket is a rare find, and it won't come close to working with an AFB. That bracket attaches to a Rochester carburetor body. It's been discontinued by GM. There used to be a $50 reproduction, but it was discontinued too the last time I checked. A later Rochester solenoid bracket ('74?) is still available from GM for $10. It also attaches to the carb body.
The solenoids themselves are readily available at most auto parts stores. Carquest sells some made by Standard Ignition (I think) for $15-30. You might want to pass on the '69 Corvette version because it requires a special clamp (not included) to position it on a '68-9 Rochester bracket. The '70 and later solenoids are cheaper and most are threaded to attach with a big nut. Ask to see their "Engine Controls" catalog. It contains photos of the solenoids they sell. Some come with brackets welded on. You might find something that was actually made for an AFB, but I doubt it.
A '69 factory Rochester bracket is a rare find, and it won't come close to working with an AFB. That bracket attaches to a Rochester carburetor body. It's been discontinued by GM. There used to be a $50 reproduction, but it was discontinued too the last time I checked. A later Rochester solenoid bracket ('74?) is still available from GM for $10. It also attaches to the carb body.
The solenoids themselves are readily available at most auto parts stores. Carquest sells some made by Standard Ignition (I think) for $15-30. You might want to pass on the '69 Corvette version because it requires a special clamp (not included) to position it on a '68-9 Rochester bracket. The '70 and later solenoids are cheaper and most are threaded to attach with a big nut. Ask to see their "Engine Controls" catalog. It contains photos of the solenoids they sell. Some come with brackets welded on. You might find something that was actually made for an AFB, but I doubt it.