Need correct coupler OMC Cobra to 1977 305

[generallee01]

HI all...doing a motor swap on my Donzi. I pulled out the 89' 4.3 V6 in favor of a fresh 77' 305. I have the correct cobra outdrive but was disappointed to find that the couplers were different. Anyone know a part# or what other years will be the same as this application? Everything else for the swap should work fine. Thanks in advance. -Pat

 

[Bondo]

Re: Need correct coupler OMC Cobra to 1977 305

Ayuh,...

You need either a Pre-87 Coupler,...
Or,..
A Post-86 motor....

 

[Faztbullet]

Re: Need correct coupler OMC Cobra to 1977 305

You are going to need the early style flywheel (V-8) also ,as the 89 has a different bolt pattern. Also the 305 uses a different harmonic balancer than the 4.3 (bigger/heavier) and the early style coupler as Bond-o suggested, the part number from some old notes was 986338

 

[chiefalen]

Re: Need correct coupler OMC Cobra to 1977 305

How about the adapter bell housing you think thats the same also ??

So let's back up a second what do you really have?? Your gonna put a 305 where a 4.3 was??

You got the right y pipe, risers, manifolds??

Maybe you should list what you do have then maybe we can help you.

 

[generallee01]

Re: Need correct coupler OMC Cobra to 1977 305

Hey there Chief,
here's what I know...and what I got. Pulled out the 89 4.3 OMC engine and drive. I have a cobra outdrive from a 305 powered boat. I have a freshly rebuilt 77' 305 to drop in. I dont have manifolds yet, however everything else is on the motor, and I do have the correct matching flywheel. The bellhousing still should be a direct bolt in if my memory serves me correct. what will the coupler I'm looking for also fit? Maybe I'll look on ebay to see what I can find on the cheap. Just need to know what other applications the coupler I need will fit. Thanks for all your help guys. -P

 

[Bondo]

Re: Need correct coupler OMC Cobra to 1977 305

what will the coupler I'm looking for also fit?

Ayuh,...

You need a Cobra Coupler for a 1985 or 1986....1987 was the Change...

 

[chiefalen]

Re: Need correct coupler OMC Cobra to 1977 305

85 was the one piece coupler, 86 was the change over to a cobra supposed to be anyway, seen stringers as late as 87.

But he needs the coupler for the cobra rubber 2 piece.

And he needs the one for a v8.

The y pipe is different wider i think.

The risers are different. What you need is the 500 dollar special the manifolds and the risers and the gaskets all in one box cheapest way to go.

You got everything off the back of the transom? And the inner plate also?

The bell housing should fit that came with the 4.3.

You need the cobra bell housing cause the 2 piece rubber coupler has to fit in that one the one piece coupler housing will not allow a 2 piece coupler to fit.

Was i clear it's late and i had a shocking evening. .

 

[Bondo]

Re: Need correct coupler OMC Cobra to 1977 305

And he needs the one for a v8.
The y pipe is different wider i think.

Ayuh,...
I don't pay enough attention to OMCs to know exactly When the cobras came out,....
But,..
I do know a crankshaft mounted Coupler for a Chevy, is a crankshaft mounted Coupler for a Chevy,... 3.0l, 4.3l, 5.0l,+5.7l will All be the same for any given Year...
Chevy went to the 1pc. rear main oil seals in 1987,.. The crankshaft bolt pattern went from 3, 1/4" to 3" at that time...

The Y-pipes should be the same Width, as the 4.3l,+ the V8s are based on the Same Block....

 

[generallee01]

Re: Need correct coupler OMC Cobra to 1977 305

whoa! Alotta info here! I'l figure out all the exhaust stuff at another juncture. Just looking to bolt the darn thing up for now. I have plenty of time before the weather turns "boatable"!