I'm also in the mitts of an old knucklehead. when i popped it apart,it had 74" jugs that where cut down to 5.405". it had medium comp. shovelhead pistons. Both cylinder's where cracked and sleeved,an ugly sight, i bought an set of 61" cylinder's that where +.020" for $300., at an AMCA meet in Wauseon,OH. I bought my piston's and assoicated parts from Kick-Start motorcycle parts inc.