Is it possible for scar tissue to become as strong as surrounding tissue 4 months after a partial tendon hamstring injury?

Unlikely. Scar tissue almost never captures the strength of normal tissue. For healthy diet: http://www.choosemyplate.gov/., exercise 30 minutes/day, drink enough water daily so your urine is mostly colorless, have safe sex, no tobacco alcohol weed or street drugs. Get HPV vaccine. Wish you good health! Safe sex: https://www.hopkinsmedicine.org/health/wellness-and-prevention/safer-sex-guidelines