Yepp. You got it! If the over-all weight of the porch is too much for only one 2X4 yardarm on each side, you could use a total of 4 verticle yard-arms, one on the front, one on the back-side of each upright, clamping the 2 top ends together with a a 6" long eye-bolt ending up with something to hang the comealong on. With 2 comealongs, and LOTS of patience and safety, you should be fine. It would be ideal if you had someone there to help run one side, lifting together without any twisting of your structure being lifted. And you are welcome!
