Question, will a sleeve seal up a vertical crack? or is a sealant applied when sleeve installed? If so I won’t weld it up.

Sleeve will work.. had a couple of blocks done

.001 press, liberal application of 640 loctite. This one had 3 of them.

The shop should use a good sleeve sealer on the sleeve but the block will determine if it will seal up the sleeve or not.
I've had one 400 Mopar block that was so thin (.032 to .015 due to core shift) on the cam side of the driver side of the block that it would not seal up after cracking the block there We tried sleeving all four cylinders also, no luck. That block was junk
Due NOT weld it up

I have had really good luck when sleeving a block - never had one leak - but I also have the block ceramic sealed up at the diesel engine shop - not sure what the product is but they pump a ceramic slurry through the water jackets of the block after the sleeve is installed.

Yes, a sleeve should seal that up no problem.

I sleeved a 454 chevy that had a huge gaping hole in a cylinder wall. Used a .125" thick sleeve w/ around .0015" press fit and a lot of green Loctite. Heat the block, freeze the sleeve, and knock her home w/ an old shortened axle shaft. Still running good in an old tow truck.

Would like to know what that sealer is

and the name and city of shop and a contact person. Birdtracker

hoping to keep this topic at the top so doubled will reply. Birdtracker

B1maxx said it was 640 Locktite..I dont know the number but I will take his word.. I have had a
couple sleeved but didnt know the sealer

I sleeved countless Chevy blocks back in the mid 70s in a shop I worked for and although I rarely do them these days in my own shop I still use the same procedure, .002" interference with Indian Head gasket sealer. Freeze the sleeve first then with a 1" thick aluminum plate a few good whacks a sledge and it's good.

It's the green Loctite 640. That's what I always used and never had any issues...even w/ some I thought may end up leaking.

https://www.amazon.com/Loctite-37424-Strength-Retainer-6-milliliter/dp/B0002KKTIG

Like Scully said, Indian Head works great. I've seen them put in using a can of spray paint and that works too. I'm sure there's other stuff people have used successfully.

The 640 to me is just part of the installation not necessarily a sealer. An old timer told me a side benefit was filling of the microscopic voids (left after boring) to help in heat transfer out of the sleeve. I don't like freezing them they get frost on them prior to installing and I don't want all that water contaminating the 640.