The Indy kit I am considering states 12.5 with 75 CC head. I can get sidhed pistons.. I am considering buying this kit used at a great price so new pistons may not be out of the question. The cam that is witht he kit is the largest befor a roller cam.. Dont know the exact specs yet. I want this pump gas and steetable.I have drove over cammed motors on the street and its no fun.