JamesE, your gearbox is F13CR, F16 is a big block engine gearbox.
Tom, i think the FDR is in one if the serial identification numbers printed on the box. If anyone can tell me thiers i can break it up and tell you what it means... i think.
Andy, 1 rev = 1 rev, not 4. 2 revs does = 4 strokes though. GR = gear ratio, and FDR = final drive ratio. These can be found in the haynes manual for the car the engine/'box came from.