Okay let me chime in..
This the reason why i say over and over again that height and body fat are the most important factor in how much you weigh and look. 6"4 300lb is not alot of weight for him and its totally believable, also he did not show his legs, legs alone could add over 30lb of body weight if they're big enough, he's fuking 6"4 and his bf is about 19%, if he was 5"8 and a bf at 8% he would be no more than 170lb, every inch adds 8lb of bodyweight, franco columbo was only 185lb and he looked much much bigger than he weighs because hes short as fuck..If you bring your bf to 8% you'll weigh around 240, which is still big but not crazy huge for someone whos 6"4..