hudkina,you have the ladders down pat.By the mid 60's GM divisions had already crossed into the same platforms.Car lineups had become A-body for Cutlass/Le Mans/Chevelle/Skylark.B and C for the big cars.The frames were the same,the suspensions components were the same.Only the divisions had seperate trim,sheetmetal and drivetrains.Even here there was a common trans for B-O-P cars,and a different rear end in Olds for a few years.The lines really crossed when the good selling Olds 88 got the 350 Chevy motor in around 1977.The Olds buyers wanted,demanded,that their beloved long lasting Olds Rocket 350/455 be put into their Oldsmobiles.If they wanted a Chevy they would have bought one!GM then put the disclaimer in their lit. that GM cars have drivetrains from different GM Divisions.When the next gen. Cars,X/J and A body came out inte early 80's,they had one or two corp. drivetrains.So Cavaleir becomes a Cimarron,a Cutlass becomes a Regal and so on.All crap,thanks Mr. Smith.Pontiacs got the short straw in all of of this.Trans-Am gets 350 Chevy motors,Daewoo junk becomes Le Mans and forever kills that name,GTO comes from overseas and has none of its heritage,like the Mustang or Challenger.G3,G5,G6,G8 gee whiz.What the hell are those,bingo callouts?When a company lets it "Excitement" division lose its way,we have to wonder what they were thinking.