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