4 day split vs westside for skinny bastards

hey guys. im 6'0, 142 pounds..im trying to get bigger/gain weight and i am in a dilemna. i am hoping someone could provide some advice. what is better for gaining size/muscle mass, a 4 day split or westside for skinny bastards?

i am currently doing another 4 day split and i wanted to change things up tommorow, starting fresh, so im still confused on which would be more efficient for my goals. id really appreciate some advice on whether to do another 4 day split or do westside for skinny bastards when im trying to gain size/mass.