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4.3L Mercruiser Alpha 1992 engine replacement

J

JohnVS

New member
After years and years of good service my engine was not properly winterized and I need to replace it on a larson lazer 200. Any suggestions on where I should look for an engine? Do I have to use the same engine size? And finally how hard is it to replace? my stern drive is in good shape. The boat has 300 hrs on it and is in great condition.
 
Easiest to replace with same engine and you can upgrade to a vortec 4.3 in some process. Vortec is better head design Chevy came out with in 96. Basically difference is heads and intake. If you have space you might also be able to drop in a 5.7 if your boat was offered with a V8 as well.

New base engines are about $3k. You would need a new intake manifold to upgrade to a vortec 4.3 might be worth getting a 4 bbl carb as well to get an additional 20-30 hp well worth it.

Easy to replace ace if you are decent home mechanic and can get a lifting device to pull the engine. I pulled mine in about 2 hours.spent a week swapping accessories from old to new engine, another two or three hours back in and outdrive on.

I would reccomend michigan motorz motorz as I had a good expereince there, but others offer similar base engines or rebuilds. I was happy I went for a new GM base engine, wasn't that much more than a reman.
 
Thank You Dieter! I checked Michigan Motorz and they have a new with 4bl carb for 4500. Is it better to get the intake manifold, elect fuel pump and carb elsewhere? Also the water cooled headers (mine are cracked from freeze) the same on the vortec as the original 1992 4.3? Anything else I need to purchase?
 
That’s the same package I bought plus the manifolds. I don’t think you’d save much as other vendors are pretty much the same but you could check center state engine as well. Both offer computable packages

your ignition should drop drop in and all accessories should also bolt up front and back only two issues may be ask if they are supplying you a metric 4.3 block. Not sure what years but some 4.3s used metric starter, flywheel cover, and side motor mount bolts. When I did same swap I had to get US thread bolts studs and starter bolts that fit my new block. Only GM would use both metric and US on the same block

other potential issue might might be oil pressure switch for electric fuel pump if your old one is a mechanical fuel pump. If that’s an issue can probably find a wiring diagram on line. If yours is already electric no issue your existing harness will work as is
 
Ever watch "Road Kill"? They were running an old and decrepit Datsun 240Z with one of those 4.3 Chevies in it. Being them, they added a turbocharger and the combo made 345 hp with 430 ft-lbs of torque. Not bloody bad!

Jeff
 
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