I have a 1996 sportster with newer 1200 engine. Im installing a 1005 twin tec igintion and it says it need's to be on tdc on the front cylinder. The marks on the timing gear and cams align up when the rear cylinder is on tdc. Do the timing marks have to be align on the front cylinder in order to run correctly? I got the bike in the condition not running and someone try to put together. any help would be useful.