Fitting a non overdrive gearbox to a 405

[Geoff Dowdle]

Geoff ,
I'm glad to see you are interested in saving cars ,
they are too good to let them rot .

The 405 diff is a 4.2 to I ratio where as 400 - 404 ratio is 3.9 to 1
So fitting a standard early box without overdrive will reduce the speed in each gear by about 10% but improve performance up hills .
Once on the road ,a 3.9 diff could be changed for the 4.2, if you felt the gearing was too low.

The other item to consider is whether the long gear lever of the early gearbox will clear lower section of the parcel tray under the dash , as all 405 were fitted with a remote shift box

Geoff D