Absolutely no reason to sell a customer sleeves when going from stock bore 1200 or even the legal amount of overbore which is .5 mm. 1200's have a 77mm bore, 1219 is 78mm bore, the new 1250 is 79mm bore. Some of the first callahan 1219's were left with full domes on the wiseco piston, ending up with the mechanical compression ratio over 11-1. We were told to fix all of those we saw when we were part of the engine building program.