well Bill,
i really am lost for words as to not being able to get a dimension for an OS part.

the thread i asked in seems to be ignored.
the correct throttle arm for a 160FT is the
OSMG9024 24981405 THRTL LEVER #4BK/#4C US$4.99

not the
OSMG9000 22081408 THROTTLE LEVER #1A-3A US$2.29

as you stated.
at any rate i ordered one and found out the size on my own.....................