In a 733, for an ALL FLAPS UP LANDING, set Vref 40+55, which gives roughly 185kts.
Regarding the approach technique, of course on a twin you can't play with the engines, but on 3-4 engines you can idle the center-outers, and it will be easier to maintain your speed and to get goaround power faster.
HD please confirm the above (which personally I've never done!).