So my machine shop is killing me hardcore, I dropped my engine November 11th 2022 for a rebuild said he would be all over it in January so its ready for spring. Well he ordered parts for it and never surveyed the block and here we are April 27th and he calls me today to tell me its cracked in a water jacket (its a new anchor)!!!!!

I found a guy selling a Gen 7 (never knew there was a Gen 7) its a new mercury 8.2L that one cylinder got nicked and it needs a small overbore which is fine sinve I have .030 overbore pistons for my Gen 6 block. My question is are they compatible?

Ask for a casting number and post here.

8.2L is a 8.2L and will say so on the block. Looking at the parts manual, the fasteners are not metric so it should be fine.

8.1L is commonly referred to as a Gen VII. It will have provisions for metric fasteners

Going to message this guy now for it.

[QUOTE=Joeyboost;4865847]So my machine shop is killing me hardcore, I dropped my engine November 11th 2022 for a rebuild said he would be all over it in January so its ready for spring. Well he ordered parts for it and never surveyed the block and here we are April 27th and he calls me today to tell me its cracked in a water jacket (its a new anchor)!!!!!

I found a guy selling a Gen 7 (never knew there was a Gen 7) its a new mercury 8.2L that one cylinder got nicked and it needs a small overbore which is fine sinve I have .030 overbore pistons for my Gen 6 block. My question is are they compatible?[/QUOT
I havent been in one BUT on bill mitchell website they advertise a aftermarket Gen 7 and it says " 8.1 l head bolt pattern" with SAE threads so Id hold a head gasket on it or a head before buying it

Will his Gen 7 block be compatible with Gen 6 internals? I have a set of .030 JE pistons in the box for my block that is now junk. I would need to use my rods and crank in this block.

cracked where? if it is to the outside they can weld it as it only holds water pressure. if it is a cylinder can it be sleeved? if it is to the lifter valley side then scrap it but I have seen plenty of blocks fixed

Gen 7 would of been an GM 8100 or 496 in the MerCruiser world.
I can't tell what the 3rd to last digit is.
Seen this casting number at the site below.

19165955...454...............1996-2001 L29

502 casting numbers from the site.
10237300...502.......96-up...4-bolt, Gen.VI, 4.466" bore
12561358...502...............4-bolt, Gen. VI
14096859...502...............4-bolt, Gen.V, HO
Chevy Casting Numbers (enginerepairshop.com)

That block, casting number 19155955 is a 454 block, not a 502. Your internals will not work in it.

I agree, IF its a block from a gen 7 from a 8.1, its got a metric deck height that converts to 10.222 , has a 4.250 bore and 18 head bolts with a different pattern. So the OP should have seller measure the cylinders with anything as 4.250 vs 4.500 will rule it out as not even a candidate.