By Evan Bleier Whether Ja Morant got down last week on 4/20 or not, the 22-year-old NBA phenom unquestionably knows how to get high. In the waning moments of the third quarter of Tuesday night’s game against the Timberwolves, the 6-foot-3 Grizzlies guard took off from just inside the free-throw line and threw down a right-handed dunk over Minnesota guard Malik Beasley that shook the rim and raised the roof at FedEx Forum in Memphis. “I always get the best view of his dunks,” said Grizzlies forward Brandon Clarke. “I was right there. I was like, ‘Yo, he just brought the ball all the way back an…