I have a 24 pantera I/O with 150s K-planes.
Last yr the boat was running in the low-mid 60s and these tabs were just fine. It did take them a few seconds to bite, but I've been told the boat can be very sensitive to the 280s.

This year I should be running upper 70s-low80s.
Should the 150s be good enough?
I've been told by merc racing and Pantera that I should be fine.
The 150s balanced the boat very well, but will the increase in speeds make a difference??? How about w/ chine walking, if it occurs at these higher speeds?
I can just get the 280s plates and bolt them inplace of the 150s.

Also will the longer tabs create more drag, slowing me down more??

Here is a pic of the 150s.

Gordo used to have the big 36" planes on his 25 AT... I think he's stepped back down to the 28's now though.

Longer tabs would require less tab down to do the same job the shorter 15's do for you now.... I think you might actually have more control over your boat's attitude with the longer planes.

I had 280's on my old 24 Outlaw. They worked fine. If your boat is chine walking, you may have issues somewhere else like loose steering joints or a bad gimbal. Tabs may lessen the chine walking but they were not meant to correct it. Tabs should be used to help the boat plane out faster, fly more level when rough or to compensate for an uneven weight distribution.

Thanks, but I have none of those problems.
Sometimes the boat would lean a bit to the port, depending on load, wind and sea conditions, but a little tab would correct it.
BTW, the pantera is 7ft beam.

Since you are not trying to correct any deficiencies in the hull or performace the smaller tabs should be fine. Remember that the faster a boat goes the better a tab will work due to increased force on the face. That's why slow cruisers have monster size tabs to do the job. You might also find that the large tabs are very hard to get set right since even the smallest movement will drastically change the attitude of the boat. Many times when a larger tab is installed, a resistor is added to the pump circuit to slow down the action-this allows for more minute adjustments and keeps the tabs from going too far and causing submarining

I have 280's on my 24 Superboat and they work great.

Did someone say BIG tabs??????

Jeezusu dude!!! . . .what the heck are those . . . you could probably stuff the boat in flat water with to much tab