im thinking of rebuilding my ka24 in my 240, i was wondering if anyone knows if it can be sleeved…and if so, how far can you bore it out, and what size pistons should be used for that bore? any other additional info on rebuilding it let me know as well please 
if you’re serious. check out www.sdsefi.com and check out thier 89 240sx. They have detailed pics of what stock looks like. I’d recommend stock bore size. no room for sleeves. www.ka-t.org is also a good stop.
You can bore quite a ways before you have to sleeve it. I’d just hone it if I were you. Are you looking for more power or something? If not, just hone the block, make sure the pistons aren’t collapsed, measure everything, and put er together. Be sure to inspect too. All the journals on the crankshaft, bearings, everything.