When I was at the airport a month ago I spotted a McDonnell MD-80 and took a picture of it and was very interested in this historic aircraft. I looked up the specs and this is what turned up. The MD-81,82,83, and 88 models all have the same fuselage length(147ft 8in) except for the 87 model(130ft 4in). They all have the same wingspan at 107ft 8in and the 81,82,83,88 carry 172 on a one class cabin except for the 87 which carries 139 on a one class cabin. So is there any way to tell the difference between the 81,82,83, and 88 models? The picture I took of the MD-80?
For Delta, it's either an MD-88, or an MD-82 reconfigured as an MD-88. The differences between the 81/82/83/88 are engine, fuel, and flight deck options. MD-87 is visually shorter than the others.