What is the difference between 86/87/88 vl calais?

[VZ Lumina 3.6L]

hey guys looking into purchasing a vl calais as a project car and wondering what the difference was between the 3 year of production, also which years model would be best? cheers

 

[87RB30VL]

Try giving this a read, might answer some questions. I'm not sure of the major differences in the year range. although I think only the Calais' were 86, not 87 or 88 but I could be wrong since mine's only an exec.