Have you tried contacting Cheoy Lee? Six or seven years ago I was able to obtain a lot of information from them regarding my 1976 40LRC. The email address I used was firstname.lastname@example.org
, the person I corresponded with was Jonathan Cannon. My props, on a 40 foot Cheoy Lee, are three blade 24 x 15.5, power is 120hp Ford 2715e.