I have a 1967 34' with 300 hp cummins 6bta. (new installation) Can anyone help with a correct prop for this set up.
I am having a difficult time getting the 2900 rpms with 20 X 19.5 X 1.5 nibrals on 1:5-1 ZF220a gears.
I started out with 20 X 21 and could only get 2600 rpms. After reducing the pitch to 19.5, I saw only an increase of 75 rpms. currently 2675rpm.
al comments are welcome