Mercruiser 4.3 - possibly blown up?

[NatedoggAZ]

OK - so I found this number on the starboard side above the starter right next to the flywheel.

Looks either like:
10066011 (most likely)
OR
11099001

I also found this on top of the header:

 

[NatedoggAZ]

Would either of those numbers be my block casting number?

Thanks!

ND

 

[NatedoggAZ]

Guess I could have used the internet machine to look it up..... looks like 10066011 is a GM block and it's legit....

 

[Scott Danforth]

here is some light reading on the 4.3. and its not complete

https://forums.iboats.com/forum/eng...history-of-the-4-3-liter-with-casting-numbers

 

[Scott Danforth]

if the motor is original to your boat, you have a 1987-1991 motor

you can jump to a 1996 or later motor if you drop in a complete motor with accessories. (dont try to mix and match)

if you need to "build" a motor. use a 1988-1991 block, use 1996 or later heads, use a 1996 or later vortec 4-barrel intake

then you can use your accessories, damper, and flywheel. you will have the benefit of the vortec heads without the issues of changing accessories. however you wont have a balance shaft