1988 seville/cuddy cabin 21' 350 swap?

[Malice]

This is my first post. This looks like a great forum, and I like the fact that you have a section just for guys like me. I am a car guy, and I have absolutley ZERO knowledge regarding boats. On to business though:

My Dad owns a 1988 sea ray 21' boat, I think it's a seville, but it might be called a cuddy cruiser. It looks just like this:

It has a mercruiser 4.3L v6 with 190hp, and a merc Alpha 1 outdrive. Unfortunatley, the 4.3L threw a rod, and the block is trashed.

My dad said he will give me the boat for free, if I put a new engine in it.

I have a 350 LT1 V8 out of a camaro sitting in my garage. I want to learn about the possibility of converting this boat from a merc v6 to a V8.

-Has this ever been done before?
-Was a V8 an option on this boat from the factory?
-Is there any good sea ray literature I can buy/download that details technical specs about boat? I'd love to have a D.I.Y. book or something like that.

I've searched the web for a couple days, and so far I've discovered the following facts:
-the 4.3 merc is a GM 4.3 short block, which means that it has an identican bellhousing bolt pattern to the 350 block
-the alpha 1 outdrive will probably blow up when I run 380hp through it via my LT1
-I need water cooled V8 exhaust manifolds, which are very expensive.
-I would have to convert my V8 from fuel injection to carburetion, which I can do easily. The throttle linkage from the sea ray throttle to a standard edelbrock carburetor is not easy though.

I've done many automotive projects before, and I know that every project takes twice as long and costs twice as much as anticipated. I would like to get a feel for what people think this project might cost and how long it will take.

Thanks for reading!:grin:

 

[WTP07]

I know there will be a few people with WAY more knowledge than I have chime in on this. (which is just about everybody)

I am pretty sure you are right about the 380HP grenading your alpha OD though. While you have a 350 LT1 sitting there, it would need to be 'marinized'...

Probabaly going to be better off finding a 350 or 350 MAG to stick in there that is already a marine engine.

But like I said, I am sure others will be happy to offer some knowledge and experience on this.

Cheers,

Randy.

 

[Malice]

Thanks for the reply.

After doing more research, I think I'll stick with the 4.3 merc. I dont' know much about boats, and if I start crusading on a non-standard project, I'm just begging for frustration.

I'd reallyl like to do do the swap at some point, but doing it on my first boat probably isn't smart.

 

[Larry]

Well I think your idea about changing out to a 350 is not to difficult providing you do not try to use your LT1 motor (this motor would need ALLOT of work i.e. cam, freeze out plugs ignition, etc...) and find a marinized 350. You would have to do some fiberglass work as well because the motor mounts fall in a different location, and yes all new exhausts. The alpha 1 drive will handle up to 300 hp without to much trouble. You can take a 4.3 ltr. motor and put a 4 barrel carb on it (i.e Merc 4.3 LX motor) and get over 200 hp, do some cam and head work and you could squeze another 20 hp out of it. The 4.3 is about 200 lbs lighter (exhausts accounts for some of this weight savings).

Good luck!