As in fastest to slowest in just the 1970 model year? If we're just talking 1970 GTO's, then the pecking order from highest to lowest would be RAIV, 455 H.O., 400 HO (RAIII), then the 400.
On the all time GTO list, I would say the 69 RAIV 4-speed, 70 RAIV 4-speed, 67 XS Ram Air 4-speed, 71/72 455 H.O., 66 GTO tri-power 4-speed.
As for slowest all-time Goat, the rare 67-69 GTO with the 2-barrel option would probably top the list, followed by the 74 GTO, 73 GTO 400, and the 64 GTO 389 4-barrel with the 2-speed auto. Of course, certain non-performance option combos may trump some of the above.
Worst combo would have to be a loaded 68 GTO convertible, with a/c, p/w, etc., with the 2-barrel option, 2.93 non-posi, and the rare chrome bumper nose. Make mine light yellow with a white top.
