90 HP 1991 Force 3 Carburetors install order

I have rebuilt my 3 Tillotson carburetors on my 1991 Force 90 HP, got all the needed parts on MarineEngine.com. The bottom carb has always leaked since I bought the boat. When I reinstalled the carbs, it still leaked out of the overflow. I have studied the carb stock #s and notice the bottom carb had a different #, After review of the parts list on MarineEngine.com, I noticed that replacement cabs were listed as top, middle or bottom carb. To my surprise, the leaking carb, which has always been on bottom, was shown to be the Top carb in the parts pricing list! Can anyone tell me what the difference is, and is this my leaking problem?

Thanks

The leak could be the float is bad, possible it has a pin hole leak and isn't
working right???
Remove the floats and put in a jug of water and see if they all float the same.

OR: the needle valve has been wrong all along??
There are 2 kinds of needle valves, one has a solid tip and a rubber seal in the seat.
#2 has a rubber tip and the seat has no seal.

Some soaks or cleaners eat the rubber in the seat or the tip, inspect them
real good.

The difference in the carbs is the bottom has the linkage or cam roller
hooked to the side.