On Seinfeld, what model and year is George's Chrysler Lebaron?

It is a convertible, but I found some discrepancy on the year. The site below says it was a 1987 in the episode when George buys it, but it is an '83 when it is mentioned in a later episode. Bear in mind that this same person thinks that is 6 years difference.

"The Mom and Pop Store" and "The Gum"
In "The Mom and Pop Store", George decides to go for "an 87 Lebaron", BUUUTTT in "The Gum", he says it's an 83 lebaron that's a 6 year difference

http://members.tripod.com/~TheBizarroWorld/Spoofs/