For your F162 you need a much more powerful fin compared to the F161. Additional the fin must be raked more foreward. That is needed because of the different "Lateral Plan" of the new one. So the different rake is not only increasing (+)/decreasing(-) the finpower also it is influenzing the Lateral plan.
Deboichet has only two different outlines:
R13 and R14:
The R19 is a R13 76cm cutted to 70cm
R16-17-18 are cutted out of a longer R14, R18=R14-77cm cutted
As the R13 was Deboichets best fin it makes sence to follow the R19 which is made out of the R13. To reach the best lateral plan take a +9 or +10 for the F162.
Hope it helps!