Thanks Kyle!

I've spoken to George in the past, and while we didn't talk specifically about this particular mod, his pat response seems to be "Don't mess with it! Just build it!". The GP-4 forum on Yahoo generates the same response. At least so far...

Those who have modified them significantly (wing chord change, IO-540 mod) have not been successful and are now in the NTSB database. I think there are only a little over 20 flying. The owners I've talked to love them, but the ones I've talked to all stuck strictly to the plans.

Seems like a perfect little airplane if you stick to the plans, but there doesn't seem to be many margins (if any) to extend the design, which I guess is the price you pay to get 200 knots out of 200hp.

I've still got awhile before I need to make a decision, but it is something of high interest to me.

Interesting point about the rudder... I wonder if the increased width of the cabin would necessitate increasing the width of the horizontal stabilizer as well.

If adding 7 inches to the width necessitates aerodynamic changes to the flight surfaces, then I'll probably back off the idea and stick with the plans.

Mark