I have a OS 160 in mine. The engine by itself is 32oz and I have a pitts muffler about 6-8 oz I think. That is about 40oz total weight with engine. I had to add a lot of weight in the cowl.

Weight= about 4-6oz of lead and a big 4200mah battery nimh(probably about 8-10 oz)= about 15-20oz

So that being said I think the g26 will be right on the money and the g38 will probably be a little nose heavy which is better than tail heavy.