FREEWHEELS DIFFERENCE BETWEEN 390/420 AND 430/500 AE

I have a 430 and a 420 automatic motor.
When I have opened the 2 motors, I have compared
the gears of the 2 motors. The two 430 freewheels are the same
than two 420 freewheels . 420 motor has 3 freewheels ( one more than
the 430).
But when I look at parts lists, the parts number of the
freewheels which are identical are differents.
420 parts numbers are differents from 430 parts numbers.
Can someone give an explication ?
420 freewheels are easely avaliable, not 430 with 430 parts number.
Pics enclosed is 420 gears on 430 gears. Diameters are identicals.
Thanks
Michel

good Michel

It has been a long time since I took them apart. Actually I might have stopped (halfway through) taking them apart on the logic if it isn't broke don't fix it. I am seeing three then two then one sprag or one way clutches on the 420 and three then two sprag or one way clutches or freewheels on the 430. I doubt I can answer your question but which number on the enclosed picture upper and lower appear to be the same?
Fran

420 FW #40 is the same that 430 FW#37.
420 FW #43 is the same that 430 FW#40.

In general is there some document in the teck reference section as to what part number has superceded what other part number. Or the opposite of superceded, going back to a prior part # Some on line parts suppliers websites seem to have some of that programmed in. It is also an advantage if you find a dealership which was in business back then in the hope they might have read and memorized all the service bulletins. It is not just husky or even just motorcycles, this phenomenon.

420 FW #40 *16 12 548 01* is the same that 430 FW#37 *16 11 265 01* .
420 FW #43 *16 12 547 01* is the same that 430 FW#40. *16 11 264 01*

I see less gears or speeds in the later 430/500 but one more freewheel in the later design in first and second gear. 420 #40 one piece 430 #37 two pieces.