Motorcycle Repair: Ironhead block clean-up, burning oil, pistons

Question
I just bought a 73 sporty "basket".The tranny is all intact but both side covers are off as well as the heads.I want to clean this thing really good before I start reassembly.Can I just go crazy with a good flush and cleaner or should I be more careful.I also have carbon on the pistons I'll need to give some attention to so any tips you have for me going back with the heads etc would be greatly appreciated.I have rebuilt a few engines but never a Harley as you can probably tell.
         Thanks

Answer
If it were me, I wuld go ahead and tear the motor down and really go through it. Your bike being a 73 and not knowing how long it sat and how many miles are on it, your bearing might be bad. If you just put it back together and it doesnt run or a bearing goes out then your back to square one. Carbon on the pistons is a indicator that the bike is either running to rich or its burning oil. You really need to mic everything so you have a good running bike
Good luck and happy riding
Mike