New Surplus Lycoming Engine Transition Assembly Waste Gate p/n 72928. TVO-435. We found these in an inventory we purchased. The Transition Assembly is in great shape and we have included pictures with measurements. We believe that this transition fits on the Lycoming Engine Models VO-435 and TVO-435 which were used on Bell Helicopter Models 47G-3, 47G-3B and the H-13 Bell Sioux which was used in the television series M*A*S*H.