Engine coupler to OMC 800 outdrive

[fredmeyer]

I have a 3.8L chevy engine with a cracked block. So I bought a used 4.3L chevy engine from a boat dealer. I got all of my stuff switched over to the replacement engine. I have come to the engine couple and its different bolt pattern that bolts to the crank and the spline is different also. My OMC 800 outdrive is a Manuel shift and the replacement engine was attached to a OMC 800 electric shift. Is there a couple that will work for me?

 

[Howard Sterndrive]

Re: Engine coupler to OMC 800 outdrive

the replacement engine was attached to a OMC 800 electric shift. Is there a couple that will work for me?

The 4.3 was introduced 8 years after the last electric shift OMC drive was made, so I don't see how that would be the case.

Unless your 4.3 is a 1985 model year engine with the 2 pc rear main seal, you are out of luck. 99% of 4.3's (1986- to present) are 1 piece rear main seal engines for which there is no coupler to mate them to your stringer drive.

If your 4.3 is a 1985 with a 2 pc rear main, then your 3.8 coupler will bolt right up.

 

[fredmeyer]

Re: Engine coupler to OMC 800 outdrive

I bought the whole motor outdrive and intermediate housing all together. I'm not sure what year the engine is. I don't know how to tell a one piece or two piece rear main. I know the 3.8 block the crank is flat with the block and the 4.3 sticks out a little bit. the two couple from both engines looks the same except the bolt pattern is different and the spline size is different. one was blue and the other one was black.

 

[Howard Sterndrive]

Re: Engine coupler to OMC 800 outdrive

If the bolt pattern is different from the 3.8, then you have identified this 4.3 as a newer motor with 1 pc rear main seal. Can you return the engine? No coupler exists for what you're trying to connect.

OMC did make a 4.3 stringer one year (1985), but it was the 2 pc rear main version and it used the same part number coupler as a 3.8
Because the Cobra drive was invented in 1985 about the same time GM changed the 4.3 crank, there was no reason to ever make a stringer coupler for the new chevy V6 engines

If that motor was hooked to an old stringer electric intermediate, somebody custom machined (and hardened?) their own coupler. Are you maybe calling the Cobra flywheel cover an intermediate?

post some pics