OMC Cobra 305 swap to 350 or 302

[23SX]

Greetings!

I recently purchased a 1988 Bayliner 18.5ft Capri 305/5.0L OMC with a cracked block (I knew this at time of sale) which is in awesome shape with the exception of the engine. I have found a 1986 350 OMC Cobra complete motor assembly and 1988 302 OMC Cobra motor assembly. Is there any changes I would have to make to use the earlier 1986 350 or 1988 302? Are the 305 and 302 mounts in the same exact spot? Both motors are a couple hours drive away and want to make sure I have good info before I go. I also found a 1990 350 OMC cobra a little further away.

Thanks!

 

[Bondo]

Re: OMC Cobra 305 swap to 350 or 302

Greetings!

I recently purchased a 1988 Bayliner 18.5ft Capri 305/5.0L OMC with a cracked block (I knew this at time of sale) which is in awesome shape with the exception of the engine. I have found a 1986 350 OMC Cobra complete motor assembly and 1988 302 OMC Cobra motor assembly. Is there any changes I would have to make to use the earlier 1986 350 or 1988 302? Are the 305 and 302 mounts in the same exact spot? Both motors are a couple hours drive away and want to make sure I have good info before I go. I also found a 1990 350 OMC cobra a little further away.

Thanks!

Ayuh,.... Of the 3 motors, the '90 350 would be the only "for sure" plug, 'n play drop-in,....

The '86 could be a 2 piece rear main seal, 'n the 302 is a Ford,....

 

[23SX]

Re: OMC Cobra 305 swap to 350 or 302

Ayuh,.... Of the 3 motors, the '90 350 would be the only "for sure" plug, 'n play drop-in,....

The '86 could be a 2 piece rear main seal, 'n the 302 is a Ford,....[/QUO

Thanks for the reply.
Yes, the 302 is a Ford motor, but wasn't sure if they used the same harness and plug? All the engines come with the harnesses. I do know they were an option as well in the Capri. The Ford is cheaper than either 350 by about $500. Would a 1990 be a "center riser" manifold? I currently have the "log style".

 

[23SX]

Re: OMC Cobra 305 swap to 350 or 302

I dont mind spending the money on the 350 but if the Ford will work $500 in gas would be nice!

 

[bruceb58]

Re: OMC Cobra 305 swap to 350 or 302

You can't do the Ford unless you get a new flywheel housing to go with it. You will also need a different coupler Down the road, you may have issues getting exhaust manifolds for it as they are different too.

 

[23SX]

Re: OMC Cobra 305 swap to 350 or 302

Yea, I thought about that too.
I see you can still get the 350 "log style" manifolds, so I will probably go with the 1990 350.

Thanks

 

[bruceb58]

Re: OMC Cobra 305 swap to 350 or 302

The 305 engine uses the exact manifolds as the 350 in case you didn't know.

If your current engine block is cracked, the manifolds will also be suspect so keep that in mind though.

 

[23SX]

Re: OMC Cobra 305 swap to 350 or 302

Yes. I know, thanks. Both the 350s come with manifolds which is good as both of mine are cracked as well.