In the pilot episode Michael Richards' character is named "Kessler" (it would be changed to "Kramer" in the second episode) and Jerry refers to him by that name. Continuity error, possibly intentional. In episode 9.8 there is a flashback to the first meeting between Jerry and Richards' character, which occurs prior to when episode 1 takes place. Jerry says something like, ". . . you must be Kessler," and the reply is, "Actually, it's Kramer." If the conversation portrayed in episode 9.8 took place it's unlikely that Jerry would have referred to him as "Kessler" in the pilot episode.
When the airplane they are flying to India on is "Somewhere between New York and India" the aircraft shown is clearly a Boeing 747. However, during the interior shots of the aircraft, it is clearly a Boeing 737 or a similar airframe.