Depending on age, aerobic condition, and level of exertion 160 may be too high or just right or even too low.
For example if you are 20 years old an in excellent aerobic condition you should be able to exercise (e.g., run) with a HR as high as 200 and still be fine.
I have no comment on the BP, other than to say the targets on usually quotes are for rest BP. BP goes up with exercise (I think).
As for headache the next day, is this sometimes or always? I don't see any direct relationship between the HR and a headache the next day...others may have something to add to this and your other points.