How do I get 800 in SAT Physics?

I prepared only from Barron’s and got 789-800 in the practice tests, but only got a 740 in the actual thing. I really need 800 for this. I found the test to be more conceptual than expected amd harder. I have PR now and I’m writing in January. Could anyone who scored 800 on the SAT Physics test give tips or advice? Is PR enough? What scores in practice tests would correspond to 800 on the actual test? I’m an international student.