Mercruiser 4.3L Thunderbolt 5 engine age

[Mike in VT]

Good evening, i own a 22 ft Grady White Tournament and the 3.7L just went,
like knock,knock,knock....... still starts easily but the knock is a harbinger of doom
we limped it off carefully. but its 34 years old. IF i could get a rebuild kit its still
min 3k to have it rebuilt.
so, my question to the group is. i have located a 'drop in' 4.3 merc with likely less than
20 hours on it. stored for 10 years. the boat owern has started it but the elec fuel pump
and alternator are getting changed. (pump is gummed up) alternator nose got dripped on.
the rest of the engine is absolutely new.
i wanted to know what age the engine is and for the life of me and all the online research i've done i cannot make the serial number determine the age.
So i am looking for guidance/knowledge.
0M081384 is the serial on the tag and the carb cover . its a 2 barrel.
does the group feel $2500 is about right for a drop in? the owner is changing the alternator and the fuel pump prior. it was winterized for all those years and its still in the donor boat.
thank you for any and all help.

 

[achris]

...0M081384 is the serial on the tag and the carb cover .

2001

its a 2 barrel.

190Hp, Vortec heads, with power steering.

does the group feel $2500 is about right for a drop in? ...

If it isn't cracked, that's a very fair price (I'll take 3 thanks).

 

[Bondo]

Ayuh,..... I'd start it up on the floor, 'n then do a compression test on it,....
If it checks out, that's a reasonable price,....

 

[Scott Danforth]

Rebuild for a 3.7 should not be $3k.

Its half a ford 460 with GM inline main bearings

$2500 in 2021 is a fair price for a complete 4.3 bobtail

 

[nola mike]

I mean, the obvious question should be why are you looking at a 4.3 in that boat? Plenty of room for a V8...

 

[Scott06]

Agreed very fair price if it runs well and has good compression

 

[achris]

I mean, the obvious question should be why are you looking at a 4.3 in that boat? Plenty of room for a V8...

Unless it's a VERY heavy boat, the V6 is a 100kg better option that a V8...

 

[Bondo]

Unless it's a VERY heavy boat, the V6 is a 100kg better option that a V8...

Ayuh,..... So leave the girlfriend home, 'n evens out,....