If John F. Kennedy was alive, he would have turned 103 next year.

Context 1: Suppose today is May 29, 2017

1. If John F. Kennedy was alive, he would have turned 100 today.

2. If John F. Kennedy had been alive, he would have turned 100 today.

Context 2: Today is Aug 14,2019

3. If John F. Kennedy was alive, he would have turned 103 next year.

4. 1. If John F. Kennedy had been alive, he would have turned 103 next year.

Hi. Are all the above four sentences correct in the context?

Thank you.