will a 76 omc upper gearbox fit a 71 lower

_dan_

Cadet
Joined
Mar 24, 2009
Messages
8
Hi i recently bought a 71 fiberform with a omc stern drive and a 350 chevy in it. of course the second time out with it the upper gear box piled up really good. i have since found a doner its a 76 omc sterndrive with a 302ford i'm wandering if all the electric shift stern drives are the same from the motor back all i really need is the upper gear box but by the sounds of things it might not hurt to have spare parts kicken around for this pile. :(

dan
 

fendersfender

Petty Officer 1st Class
Joined
Mar 23, 2005
Messages
317
Re: will a 76 omc upper gearbox fit a 71 lower

OMC made only 2 styles of upper gearcases....a high profile and low profile....i THINK all electric shifts had the high profile gearcase.....as long as you have the same style gearcase, it will bolt up...BUT, the differences in the gearcases was the gearing...I'm not sure what the gearing was in either of those applications...should'nt be a huge difference in gearing for a 302 vs. a350...here is a good parts website with some good info... http://www.sterndrive.info/
 

WizeOne

Commander
Joined
Mar 23, 2008
Messages
2,097
Re: will a 76 omc upper gearbox fit a 71 lower

Electric shift uppers came in both High and Low Profile. When they went to the Hydro-Mechanical drives in '78 they dropped the high profile configuration.
 

_dan_

Cadet
Joined
Mar 24, 2009
Messages
8
Re: will a 76 omc upper gearbox fit a 71 lower

thanks so it sounds like the parts are the same just have to match gears.
do these drives only have a gear ratio in the upper gear case i have found info on that but is there different ratios on the lower leg or are they all the same. haven't been able to find info on that yet?
 

_dan_

Cadet
Joined
Mar 24, 2009
Messages
8
Re: will a 76 omc upper gearbox fit a 71 lower

yea i found it :D

All lower gear housing ratios are either 2.0:1 for the four-cylinder engines or 1.83:1 for the six,, and eight-cylinder engines.

that answers my question
 

_dan_

Cadet
Joined
Mar 24, 2009
Messages
8
Re: will a 76 omc upper gearbox fit a 71 lower

ok new problem the differece between the high profile and the low profile upper cases does this mean the overall hight of the leg is different i have the high profile case and if this other one is a 76 appently they didn't make them any more so that means it is a low profile. if i get the whole leg can i just bolt it on and go ?
 
Top