My strong grip doesn't work past the long irons, only on short irons.

For my long irons and hybrid and 3 wood and ESPECIALLY the driver, I cannot use a strong left hand grip. Big hook. Big scary hook with the driver. When I completely weaken my left hand grip I have no problem with the driver except for maybe an occasional push. Its a power fade (I know that's an oxymoron) most of the time. If I try to draw it, with even a neutral grip, it's a massive duck hook. Am I just taking the club too inside? Should I practice taking the longer clubs back more outside (club head well outside the hands)? I have a stocky build. Kind of like Carl Pettersen. I'm 5'10 and weigh 215. Do I need to have a more upright swing based on my body type. Keep the club more out in front of me?  For now, the weak left hand grip is saving me off the tee but it would be nice to hit a draw on the dog leg left Par 4's. I used to have no problem hitting a decent draw off the tee. Suggestions? I believe my posture and alignment and ball placement are fundamentally sound. Weight balanced on the balls of my feet. etc. 

The weak left hand grip is working just fine with the driver x two weeks. I just strengthen my right hand grip slightly. I can even hit a slight draw with it if I try not to consciously clear my left hip and just aim the butt of the club at the ball on the downswing. This prevents me from clearing them too fast, getting stuck, and hitting a big push---it doesn't duck hook because of the weak left hand grip. When trying to hit a draw it feels like I am just using my arms (on the downswing) but of course my hips are turning. Gives me a really nice slight push with a baby draw. Pretty powerful for what feels like an arm swing. If I really want to clear the hips I have to aim pretty far left and I hit a power fade. I still use a strong left hand grip (3 knuckles) on the irons unless I'm chipping and there a weak left hand grip feels better. Had to scrap the interlocking grip. It doesn't feel right with a strong left hand grip. Using the Vardon. And really liking it.