Do I need a pink slip to sell a car?

So, like my grandpa had this old chevy bel air convertible from the fifties that he loved. before he died he told me that if i promise to take good care of it for him i can have it so i was all that's cool. now that he's dead i want to sell it since my parents got me an acura when i turned 16 so i don't need another car but i could use the cash since coachella tickets are on sale. the problem is my grandma hasn't put the car in my name yet and my parents are being ***** and won't front me the cash for it. since it was legally given to me can i sell it without the pink slip?