Cutting it down 3/4" will make it feel somewhat lighter, not a crazy difference but you'll probably feel it. The secret grip with the 17 gram disk in it, (which is the way it is usually supplied) will weigh 107 grams, so that's adding 57 gm to the club over the stock grip weight. The club will then feel heavier, but it will also move the balance point quite a ways up towards the grip. So it will have a considerably different feel than stock.
A friend of mine did exactly that (cut 3/4 off + secret grip)with an Adams 9088 UL and hated it, I hit it a few times and it was OK, but I didn't really care for it.
I put a 90 gm shaft in a RBZ cut to play at 44.25 with a secret grip on it and absolutely loved it for a few weeks but it felt pretty heavy and got to the point that I found myself swinging too hard with it. So I put a standard weight grip back on it and it feels great.
Bottom line? Back weighting feels different to different people. You won't "mess it up" or make it unplayable, if you don't like it, put on a regular one, it's just a grip.