Hachul,
The 2.4 is a good choice but watch your weight. I have a 2.4 I am installing it in a 28% Cap21 96" wingspan 14lbs. a 3.2 would make the plane unnecessarily nose heavy at over 17lbs. A 2.4 may not be enough to 3D this plane but a Cap21 is not really a 3D plane anyway. If you look at RC Show Case web site they have a spreadsheet
that shows their recommendations for their engines. A 2.4 is about 40cc and it pulls the same if not a little more than a zdz 40RV. According to RC show Case a 40cc engine will pull 20lbs max, 14-16 sport and less than 14 for 3D.

I've read where allot of people were installing a 40cc gas engine in the GP Giles 202. (72" wing span) Some may like this set up some say it turns the plane into a bomb. (to nose heavy) I think the most perfect plane for a Brison 2.4 is a wide body 76-78" aerobat plane. Kangke USA Texas Hurricane is a very good plane for the 2.4. The old Yellow A/C Cap10b is another. Something that can handle the width of the engine (Walbro carb and slimline muffler) without carving up the cowling too much.

The GSP Yak may be a little small for the 2.4 but again watch your weight. Build it like a strong .60 and not like a small big bird. In other words watch your battery weight, use one strong digital servo instead of multi servos.

If you do that you should be okay.

Good Luck


jds