Did he use such a large engine because it was tail heavy, or did he add weight to the tail because of the engine ?

I vaguely remember this plane from the 1990's, I believe. I had the Porter , got it in 1994. I believe they advertised this model at a lighter wieght and with a much smaller engine. But Altech airplanes were made in the Philippines, and we assume from the landfill near the closed Clark AFB, and were very heavy models and notoriously weak. It was common practice to beef them up. My Altech Porter actually had some bark on the wing. And a friend swears his came with a hoof print on it !!

But, once you re-engineer one of these mostly plywood tug boats, they do fly very nicely , with enough power. They are heavy and fly very well in gusty conditions because of their high mass.


So here is my opinion:
Although, I doubt they ever advertised the plane to carry that much engine, it wouldn't surprise me that it eventually did.