a few things could cause this.

the shaft could be too stiff, though a stiff shaft generally gives better acurracy and makes you feel manly ect. a more flexable shaft will give you more distance.

also you could have loft too low. or the shaft could have a bend point too high, a high bend point will give a low trajectory.

you could also have a too flexible shaft with a low bend point which rockets you ball high with high spin and ballons your ball giving you bad distances

thoose could affect distances, but swing speed, thats a bit tougher

that could be the club is heavier and harder to swing? i'm kinda stumped. generally for every inch in shaft length you gain 2mph and 6 yrds i think it is (havenlt looked into thoose stats in a while)

now the 6yrds is dependant on weather you still hit the same sweet spot and everything else is the same but the swing speed should increase regarless of how well your contact it.

180 7i is pretty good distance you should be at lease driving 250 if not 270.

could you post your swing?