Dave -
I'm assuming you have the wedge in down posistion
Is the 750 pretty much full in the back locker?
I would probably add another 750 or at least 400 on the the side you are surfing on the seat and possible another 400 in the front. Get it to lean.
We are in a Vride and I fill the back locker as much as possible until we can hardly close it. Then put another 400 on the seat in front of the locker and we ride at around 10-10.6
Not a macking wake, but pretty decent for a smaller boat.
You can also check out
www.wakeoutlaws.com and
www.themalibucrew.com Lots of peeps at WO have Malibus and if you do a search on both sites you will find tons of good info.