1993 Seaswirl with omc cobra 4.3 engine seized

[mannys]

Hi all, I purchased a 1993 seaswirl with an OMC 4.3 cobra which has been seized since one winter it wasn't winterized properly.
I've tried numerous ways to un-seize to no avail so I'll pull the motor out. I've removed the outdrive from the boat.

I see on this forum people say I can pop in a motor from a GMC pickup from certain years.
Can anyone say what years pickup truck I need to take an engine from? I'd like the swap to be as simple as possible and not need mods to the replacement engine.

Thanks!

 

[mannys]

I'm checking junkyard stock at car-part.com and I see many engines available from the chevy astro. is this compatible/same block as the omc 4.3?

 

[Bondo]

Ayuh,..... Welcome Aboard,.... Any of the GM 4.3l motors of 'bout the same vintage as yer's is a direct swap,....

GM 4.3ls of a different vintage can usually be adapted to work with whatever vintage ya start with,....

You'll be swappin', Just the Long Blocks, not complete bobtail motors,...

 

[Scott Danforth]

Welcome aboard

make sure you change the block core plugs to brass. I would also recommend putting in marine head gaskets.

if the block was not winterized, the exhaust manifolds would also be suspect. I wouldnt even bother testing them, I recommend getting new ones.

 

[mannys]

Welcome aboard
.

if the block was not winterized, the exhaust manifolds would also be suspect. I wouldnt even bother testing them, I recommend getting new ones.

Hi and thanks. the boat was winterized but apparently not good enough and thats why the engine seized so probably worth testing manifolds . how do I test them?

 

[vasy]

Something like this: https://www.youtube.com/watch?v=8D16i68nHmE