If you're 6' 2 and 275 and don't get any push power you're doing it wrong. You're perfect for prop. Get down, get your feet back, bend your knees and explode. You also need your locks and back row to push. Technique plays a huge part at prop. It isn't just being big. I'm 5''11 and 215. At my club I could outscrummage (I mean wreck) much bigger guys because I have good upper body strength, good technique and I made an effort. A lot of really big guys think they can do it by just leaning. 6' 2 and 275 isn't going to make a lock. Too short and too heavy to lift.
I hate to tell ya but your kinda big to be playing lock your team has a wide age range so your one of the bigger guys so play wehere bigger guys are needed if u don't get any push power from the stance the find one that works better for u im 15 play U19 im 115-120 pounds 5'2 and play open side flanker