Those are just the various ID numbers that were fitted to the engine. Typically they indicate minor calibration revisions as the model year progressed.
If you want to go with Holley, then I’d suggest a basic 600 vacuum secondary carb. Holley offers them refurbished for a couple hundred less than new.
About the only changes you’d need to make are to the fuel line to the carb. You’ll need to work up hoses and an inline filter. The carb has the setup for the auto transmission kickdown. You’ll need a ball stud for the throttle linkage and the choke is electric vs hot air, so that needs to be powered.
I just want to stick with the 4300 set up and have two carburetors and one being a backup. I do want to purchase a 600cfm 4300. My car started running better after I went out of town and gassed up. I live in small town on a big lake and all the service stations are old. I gassed at a Walmart station in the nearest larger city, that is very busy, and just had new tanks installed.
So you didn’t have to make any modifications to the linkage or kickdown? I think your carburetor is for a 71 Lincoln, if so, didn’t the 71 Lincolns have C6 transmissions and any difference in kickdown for the 69 FMX? I went searching for a carburetor like yours with no luck either.
