While a cure like 'stop leak' doesn't come with a guarantee, one fall about 35 years ago I put rings and bearings in an std.88.  I must have disturbed a sleeve as in the spring I found the crankcase full of prestone. One can of 'bars leak' and no problem to this day. I wish you similar success if you try this, however if you remove and reinstall the sleeves you'll be certain of a better job with no more sediment remaining in the water jacket.    Best of luck!    Murray