In 1965 Grumman Aircraft decided that turboprops were a thing of the past. The GII shares the same forward fuselage and cross section as the GI. There are more differences than similarities. The most obvious difference is the two rear mounted Rolls-Royce Spey axial flow turbojet engines. The other differences include a new swept wing and tail. A similar size fuselage to the GI seats 10 in a typical executive configuration. The GIIB is a GII with a GIII wing. This wing is eight feet longer and carries 4,961 pounds more fuel with a 921 nautical mile increase in range. The first flight was a production standard aircraft, which first flew on October 2, 1966.