Chris craft 312 omc 460 outdrive gear question
 

Hello everyone,

I am new to the offshoreboat world as my other hobby is jeepin, it was always a dream of mine to have an offshore boat and now I bought a chris craft 312 from 1988 with the omc king cobra engine package :)
But their is one thing where i'm not shure of, witch is the upper outdrive gear ratio. Because my strb upper gear is broken and now that i have taken it out i saw that my upper gear ratio is 21/16 and this sould be 21/17 with the omc 460's.
Is this bad or should i just leave the 21/16ratio and put other props on it instead of the stock ones.

Thanks Rien

For the 7.5 - 460 Ford - 21 / 17 should be in the upper for this OMC Cobra OEM stock and then 21 / 18 should be in this for the High altitude apps above 5000 ft.

Forgot 21 / 16 in the OMC Cobra upper was used for the GM 5.7 and a 21 / 17 for high altitude above 5000 ft. Again OEM OMC stock for the upper Cobra's

Thanks for the reply ;)

The problem is that i can't afford two new upper gear sets including all other expences, because the port side outdrive will also have the 21/16 upper gear ratio and if i want to put it back to oem than i have to replace both :s so is there maybe an other solution ? 21/16 and an another pitch ?

Thanks