RE: What about GMS 76?
GMS engines are great. They are strong runners and reliable. I have a couple of .47s and a .61. The 61 really hauls for its size, and the .76 is a bored and stroked .61, so it will give heaps of power. Theres a couple of guys at the club with GMS .76s and they swear by them. They fly circles around similar sized OS engines. I think this is partly due to the cost - they aren't afraid to push them to their limits like they would be with an engine that cost nearly twice as much. And the big GMS muffler (same as the Tower muffler) really gives it a boost.