wrong, deadheading counts as duty. therefore, you cannot show up for a deadhead 7hrs after completing duty the day before. you can show up 8hrs (assuming less than 8hrs of flight time the day before), but you will be on reduced rest. you cannot do a deadhead home on day 7, as that is duty and would voilate the 24hrs off in 7 rule.

now, you could do a part 91 repo flight after completing 8hrs of 121 flying, and that is cool, assuming you do not go over the 16hr duty day.

remember, the legal rest starts and ends when you go off or come on duty. not when you start/stop logging flight time.

also, most union contracts state the the 24hrs off must be a calander day, and must be in domicile. (i pity those that don't have that rule)