I have a 2001 260SX e/w 496-375Hp Volvo and a DPX Duo Prop drive. I am thinking about increasing power and am wondering if anybody has any experience with this on a 260, and if so what the results are as far as top speed, handling etc.
Currrently I run about 60 mph @ 4600-4700RPM- which is the most RPM I can turn.
I would like to run in the mid 80's and wonder how the boat would handle at that speed and even if 80's are attainable on the 260.
I would like to keep the upgrades to around $30K and they must be reliable, I'm not looking for "a fix-it everytime you run it" boat!!
Any info anyone has will be most appreciated.

Thanx

We put 625 Hp in a 1997 260 and it would only do low 70s. The boat handles well without tabs. It took a little practice with steering so it wouldn't chime walk on smooth water.

Are you saying that the 260SX doesn't respond well to increased power? Is this because of the hull design or another factor?
I would have thought with the addition of 250HP speed should increase approx. 20-25mph using the 1mph/10hp guideline.
At what speed did the chine walking appear and disappear??