so you used a normal length driver in your before and a longer one in the after?
How do you know if you've actually gained anything? Stick with one club when you're comparing befores and afters, otherwise, you don't have a clue of your progress.
next, start training with bands. This will teach your body to not 'slow down' when near the range of motion but to keep on creaiting increasing force.
Obviously some lifts can be done with bands and others can't (squats, deads, bench are good for bands, oly lifts... not quite so good for bands).
It looks like you're doing Oly lifts which seems to help out... a lot (at least me doing oly lifts has helped my distance a ton).
You'll also want to work a lot of your trunk rotational ability and you'll want adequately flexible (but powerful) shoulders and lats. The wider the swing arc, the more power you'll make. The only way to do this is a larger turn and getting your left arm up and across your body (if you golf, you know what I mean).
lastly, wrists and fore arms. the stronger and looser that they are, the better for your swing speed.
This is what I've been able to piece together on my own over the last few years.
It also helps if you have a fundamentally sound swing...
and are tall... you 6'4 bastard