A little added info. The major part of the conversation was replacing the L-11 with a L-13 which gave the ship added power. Then they started to replace the inlet filters. The first ships and the D models had the squirrel cage and a hooded type engine cover. They started to convert those to the sponge type filters and the screen type engine cover. This reduced the amount of FOD (foreign object damage) to the engine but it also reduced the air flow into the engine which reduced it's power. That became fact because Dan Lukken's gun ship Croc 188 had the hooded engine cover and the squirrel cage and it would out fly any gun ship in the company. The rest of our ships had the conversation done to them and we never had the same power as his ship. Why do I remember that kind of stuff but are always misplacing my car keys? Sometimes getting old sucks!