Join Date: Nov 2003
Location: Houston Texas USA
Okay you said "...My 1980 Spider is often described in literature and articles as a 105/115. Does this mean it isn't a 105 anymore, but it isn't quite a 115 yet?"
In answer to your question No, your car is definitely a 115 chassis. However the term "105/115" doesn't refer to a specific car, it's just a made up term to ease the parts ordering process. In American car catalogs, you would see the phrase, fits 1970-1981 Camaro/Firebird.
Well there is no such thing as a Camaro/Firebird, a car is either a Chevrolet Camaro or a Pontiac Firebird; but the car are very similar and the majority of the parts interchange. Similarly "105/115" means that many parts that fit the 105 chassis also fit the 115 chassis.
This isn't the first time this happened. The early Giuliettas are referred to as "750" cars, as Alfa developed the car it changed the designation to "101". In parts catalogs, you see the term "750/101" used to refer to, parts that fit both early and late Giuliettas.
Hope this helps