My gearbox changes fine on all except 4-3, nasty clunk noise and I can feel it click into place. Not smooth at all.

Is it on the way out ?

Trying to identify what Ford 4 speed box it is, so I can source replacmnent.

Has 2824E-7006C stamped on the side ?

Sounds like sychromesh has gone on third gear.
Not sure on thr number on the box but try Burtons for info, they have lots of information on all Ford Boxes.
I'm guessing yours could be a Bullit type as fitted to escorts, lotus etc

I am sat here with the Burton Power catalogue and it says that the 'Bullet' gearbox was fitted to the Cortina Mk1, Lotus Cortina Mk1/2, Escort twin cam and Escort RS/Mexico.

The gearbox fitted to all the rest of the escorts was the Type 2 gearbow, which is what it most likely is.

Adam

Eventually found this again squirreled away among my favourites, you might be able to determine your box from this. Cheers, Steve.
http://mujweb.cz/www/murdak/data/e-prevodovky.htm