The boat I picked up recently ended up having a Gm 5.7 SGI Casting # 1409360 with a cracked block, something I knew might be a possibility. I have found another block but I am unsure if everything is going to match up correctly or if I need to search for a different block? The block ID is V0531TYZ . 1975, 350, 165 HP,4 Bolt. Any help would be great!

Ayuh,.... 'n what vintage is this one,..??

The cracked block is in a 1982 Hammond Challenger MK II. Someone had already done a motor swap long ago

Hell, it's either time for a big block or an LS. Those challengers love power.

the '75 350 block should be a two piece rear main seal and the 5.7 140*** block is probably a one piece seal so the crank wont interchange. the 140*** number is missing a digit from what I can find and the TYZ is a use designation not the casting number of the block itself.

you are missing a # with the block in the boat.

Ryan;s had a 23* 383. Went over 80.

Where are you located ?

North Minnesota would be my guess.

I know it would love one but the checkbook isn't ready for that yet. i am trying to stay with the 350 because I am new to this and its easy to work on as well as lots of parts available.

Thanks for the information sorry about the missing number. I found that you are correct.