Help finding replacement for my 1998 4.3l mercruiser motor due to freezing.

[Wnafabrication]

Hi all, I’ve done a small amount of reading as to what is needed to replace the block on my motor. It blew out a freeze plug and after replacing and restarting, all seemed ok until the frothy mess started to emerge from the Pcv line... so that was yesterday and today I’m wondering, what is the most cost effective way to get a replacement block? I’ve read that the s10 has this motor, but there are some differences I need to watch for, and also, should I be draining the oil/water from this immediately to avoid damage to the crank bearings etc?
Any help would be appreciated, It’s the family boat and we just don’t have the funds to buy a replacement motor.

thank you very much,
Trevor.

 

[Wnafabrication]

Will a 2002 4.3 out of an S10 extreme swap over? I found one used with 200k

 

[Chris1956]

Gee, rebuilt marine 4.3L blocks are pretty cheap. Last I looked a long block was less that $2K.

If you are looking to buy an automotive block(with the right or close camshaft), you will need to swap over the freeze plugs, alternator, starter, thermostat housing, exhaust manifolds, distributor/ignition system, carb, and some smaller stuff

 

[Scott Danforth]

first, there is no such thing as a freeze plug, they are core plugs to get the core casting sand out during the foundry processing of the block

second, a motor with 200,000 miles on it is a core for rebuild and not a good running motor. you should be able to find a low-mileage motor for $300 on sites like car-part.com

since your motor was a 1998, any 1996 or later 4.3 V6 from any truck would work. so would any 1996 or later marine long block or a bob tail

if you go truck motor, you will need to strip it down to the long block only as the block and heads are all that you will use from it.

you will need to buy a new marine circulating pump and a new marine intake and exhaust manifolds as they are most likely busted from freezing from poor winterization.

so a running low mileage junk yard will cost you $300, a gasket set is $140, a brass core plug kit is $11, new intake manifold is $300, new exhaust manifolds and elbows are $550

a re-man v6 long block is about $2500

a new bob tail is about $7k

 

[havoc_squad]

If I ever get an I/O again, the alpha one gen 2 4.3L vortec V6 or 5.7L V8 vortec engine is the way to go.

If you don't bust the exhaust/intake manifold from freeze damage, it's probably the best value repower option for I/O.

 

[Wnafabrication]

Hey guys, I got this running with the s10 motor. Swapped over all the marine essentials, put it back together and she’s running fine. Only thing that was damaged was the block.
thanks for everyone’s help!