Part Identication

[GLS]

Hi new to the forum, I'm looking for some info on my cylinder block. The casting number on the block next to the freeze plug is 852-7738. Can't find no info when looking up part number. I'm trying to find a replacement block that will work. I believe that my motor is a 79/80 mercury 140 inline 6. Serial number stamped on the tag and block is 5742675. When I look up under the serial number it tells me that 852-7739a3 or 852-8310a4 were the blocks used, I just want to verify that they are the same as what I have. Any help is greatly appreciated. Is there a website for looking up casting numbers?

[boats.net]

If the number 5742675 is stamped on the freeze plug then yes that is the serial number to use to find correct parts, any number stamped in block or casting are not valid serial numbers and can't be used for identification.

[GLS]

Ok Thanks for the reply