SFO - Transfer from Terminal 2 to International Terminal

Next month, I am flying with Alaskan Airlines from San Diego to San Francisco and arrive at 1602 - I think at Terminal 2. Do I have enough time to transfer to International terminal to catch VS20 to LHR which departs at 1750?

Am getting slightly nervous regarding time needed to make the transfer.

Yes that should be enough.

You will have to exit security from memory and re-clear security in the International terminal which can get busy but that should be more than enough time!

You will have plenty of time. You can catch the airtrain (red line) but I find it's quicker to walk through the terminals as you will come out at the A side of the International terminal where VS departs. Checkin counters are on Aisle 9/10 . Will take about 15 mins from Plane Door to checkin desk. Boarding will likely begin at 16:50 so checkin before you leave SAN.