Gearbox oil

Has anyone changed their gearbox oil to make it a bit slicker when cold?

If so, what oil did you use and did it make much difference?
 
Thanks for the suggestions, i've done a bit of research and found that gearbox oil is available in GL4 and GL5 spec. Which one is correct for the 197? Apparently the GL5 is newer but can eat through brass components in the syncro?
 
what acutal tyoe of oil is needed in the gear box? got to the stadge where i have to do mine now, can i get the correct stuff in halfords??
also anyone done an how to guide? or got pics of the plugs u pull out?
 
Got fred to do mine, not sure what he used, didn't seem to make too much difference lol. Its a lot nicer when the cars warmed up though. Slots all gears very nicely.