The general rule regarding low blood pressure is if there are no associated symptoms the lower the better. The measurement you have listed is not too low and should not be a problem.
It is appropriate to reduce blood pressure and no heavy lifting for dilated aorta. For a perspective, an aorta vessel larger than 4.0 cm is considered an aneurysm, and if and when the diameter is 5.0 cm or if the size increases more than 0.05 cm in year, then there begins to be concern for a rupture and may require intervention.
Thanks for your question and if you have any further questions or comments you are welcome to respond. Take care,
Ken