Engine and rear-brakes were the most standardized differences. Carbs were different on early 2800's compared tolater 3.0's, euro 3.0's were injected. Trans of course went through upgrades over time (as stated by another poster.) Master cylinder and vaccuum booster were usually different. Front strut-to-knuckle interfaces beefier on later cars. Over time, the bodyshell became heavier - meaning the early 2800's managed to be lighter (all other things being exactly equal) than their later 3.0 brethren. For a street car, these diff's might seem subtle, but the 2800 engine is abit more fun to drive (in my experience) than a 3.0 (all other things again being equal) Lower torque for sure, but spins up differently and for some this is a good thing to have the power band higher.