Advice on stroker build with cracked cylinder

I've had a cracked cylinder in a 440. After a new sleeve was put in, as a test we lightly skim-bored the new cylinder surface with a (same KeyWay) cylinder bore.
After that it became obvious the bore hadn't touched the area where the original crack was. The sleeve had conformed itself slightly to the old cylinder shape. (I have pics of this somewhere but need to put them on my site)

Given that experience, and you're saying you will race the engine anyway, I would say do a 'partial or half fill' with concrete in the block to limit any further distortions and have an ease of mind.