Jim You don't' run longer sleeve, don't know who you talked to. You over bore the cyl almost to the bottom, you leave a ledge at the bottom, that holds the sleeve in the block and keeps it from being pulled down and out of the block. Also the bottom of the cyls are to specs, if you ran a longer cyl sleeve, you would then find that your rotating assembly would hit. The head holds the sleeve in at the top. Andre " A.J." Jacobs, web page http://southtexasamc.tripod.com (830)-980-3165 , akjamc@xxxxxxxx Owner & Proprietor, South Texas AMC