Replace 3.8 OMC outdrive with same year OMC from 5.7 Chevy

[bookemz]

I have a 1983 StarCraft 19' Islander Cutty Cabin in the process of restoring. It sat for the last 9 years but is still in very good shape. It has an OMC 3.8 litre sterndrive Im not sure of the size of the outdrive it fell victim to electrolosis and needs replacing. My question is I have a parts boat with a 5.7 OMC will I have a problem using this outdrive with the 3.8? The V8 OMC came out of an 18' fiberglass boat the same year.

 

[tarheelebbtide]

Re: Replace 3.8 OMC outdrive with same year OMC from 5.7 Chevy

Don't know a thing about OMC's but assuming they are not all that different than Merc's in theory, I can say that the gear ratio on the outdrive for the 5.7 is going to be too "tall" for the 3.8. It's going to lug, you won't be able to develop full RPM's and aren't going to get any power out of it.

 

[J JACKSON]

Re: Replace 3.8 OMC outdrive with same year OMC from 5.7 Chevy

i think the hole for a omc is bigger than the one for a mecruser if you redo the transom you could make it fit the boat but i don't think it will bolt to the engine. why don't you put the 5.7 and the mecruser in your boat that is real good combo

 

[Don S]

Re: Replace 3.8 OMC outdrive with same year OMC from 5.7 Chevy

i think the hole for a omc is bigger than the one for a mecruser if you redo the transom you could make it fit the boat but i don't think it will bolt to the engine. why don't you put the 5.7 and the mecruser in your boat that is real good combo

He's not talking about trying to use a Merc outdrive, only as a comparrison of having the WRONG gear ratio.

 

[J JACKSON]

Re: Replace 3.8 OMC outdrive with same year OMC from 5.7 Chevy

my bad i miss read his post

 

[tarheelebbtide]

Re: Replace 3.8 OMC outdrive with same year OMC from 5.7 Chevy

Hey, I misread my own posts sometimes!

 

[chiefalen]

Re: Replace 3.8 OMC outdrive with same year OMC from 5.7 Chevy

With a little work and if, a big if, the motor and the out drive are good, and you have room in the hole, and you do some modification you could leave the intermediate drive.

And put the out drive on and the 5.7 in the hole.

Whats the 5.7 in? Maybe you want to fix up that boat?

I'm faced with a a similar problem.

Got a 140 hp merc with a good gimbal good motor bad out drive 85'.

Bought the boat for the motor to put in my omc boat.

Boat is a bow rider with bad floor. Good trailer.

Everyone says i should get a 1300 dollar out drive forget the cutty with the omc.

I want the cutty with the 140 in it. omc out drive in my signature.

Maybe you can fix the boat with the 5.7 in it, can't use a 800 drive on a 400 motor never can prop it right. Wont do it, take my work for it.