98 5.0 Mercruiser Replacement

[Bwellman2]

Need to know what kinds of engines/blocks can replace a 98 5.0 Mercruiser. Looking for any options that might work. Serial number is 0L083828 any help or guidance is greatly appreciated.

 

[o2batsea]

The 5.0 is a Chevy small block. It is one of the most common V8 engines ever produced. Your options are sort of limited to the same type engine.
You can go up in size with a 5.7L (350) in the exact same footprint. That is, more or less, the identical block with taller deck.
Usually you can find good used running take out (RTO) engines locally on Facebook Marketplace and Craigslist. You are buying as-is and risk is all on you. These engines tend to be fairly inexpensive as they should be. You'll want to run a thorough health check before buying. That will include a compression test and a cylinder leak-down test. The seller should agree to this with no hesitation otherwise walk away.
There are several firms that recondition these. Jasper, Michiganmotorz, etc. They sell with warranty. When you buy a remanufactured engine, you will take all the external parts from your current engine and move them over to the new one. At this stage you'd probably want to install new manifolds and risers, circulation pump, and rebuild the seawater pump (if equipped) before putting into the boat. They also supply turn-key remanufactured engines that are straight drop-in.
If you are considering buying new from Mr Mercruiser, you can use the 6.2L. These are a "stroked" version of the 5.7 small block. At that point, you should consider the cost/benefit of repower over newer boat. The new 6.2 is roughly $24K not including the shipping, tax, installation, and ancillary items needed.

Like airplanes, you're pretty much buying an engine and you get the boat for free.

Now, with all that said, other manufacturers made or make marinized versions of the Chevy small block. Volvo, Pleasurecraft, Crusader, just to name a few. In addition, there are several marine diesels and many many other configurations such as V6, I4 that will "fit". However, engines and drives must be matched for gear ratio, so putting a different engine with higher or lower horsepower will require a change in the stern drive.

 

[kghost]

A 5.0 and 5.7 of the same model years (as they use the same for a few years) are an easy swap. All external parts are swappable/interchangable but confirm ignition modules (timing map) are the same.
As said many places to find plug and play engines as well as complete with all parts like manifolds, ignition and carb when someone does a repower.

I agree Facebook Market place is a good source for used engines but do your research. If it sounds too good it may be a scam...