Looking for help with engine ID from serial numbers. Mercruiser big block inboards.

[tmh]

So I've got a 1988 Mercruiser MIE Blue Water 7.4L inboard engine that needs a new block or full drop-in replacement. I located a pair of nice used engines but the current owner doesn't know the year (from 1988 Sea Ray , same as mine) as they look fairly new. He gave me Serial #'s but I can't figure out what year and generation they are. Maybe someone here can help. Here are the # the seller gave me. I need an opposite rotation engine not sure either of these are,

B559512 and B522904

Hope those numbers are correct.

 

[alldodge]

So I've got a 1988 Mercruiser MIE Blue Water 7.4L inboard engine that needs a new block or full drop-in replacement. I located a pair of nice used engines but the current owner doesn't know the year (from 1988 Sea Ray , same as mine) as they look fairly new. He gave me Serial #'s but I can't figure out what year and generation they are. Maybe someone here can help. Here are the # the seller gave me. I need an opposite rotation engine not sure either of these are,

B559512 and B522904

Hope those numbers are correct.

Unable to find the serial numbers listed, my guess is the letter is different. Serial numbers for 7.4 for 1988 to 1992 were 0B788366 THRU 0D715493

If you look back by the distributer and directly below it in the top of the block below the head there will be a casting number. We can look it up