The Cowley and Oxford both sport superb, accurate rack and pinion steering like their smaller sibling, the Minor. The Isis has a steering box, which is perfectly good, but it is not as nimble as the smaller Morrises.

Make sure you keep up with the maintenance of the rack or 'box - they need to be full of EP90 hypoid oil.
The Isis' steering box can be adjusted if it shows excessive slop in the straight ahead position. Use the locknut adjustment on the top of the 'box.

I strongly recommend replacing all rubber suspension bushes, then you can appreciate just how good the steering and suspension on these cars really is!

Below are the BMC part numbers for the rubber bushes and a scanned diagram from the Parts Manuals:
Oxford/Cowley
 
Isis

The Cowley, Oxford and Isis all sit on torsion bar suspension up front and have telescopic shock absorbers all round, so playing with ride height and level of damping is quite easy.
The Oxford's Indian built cousin, the Hindustan Ambassador, has a front anti-sway bar fitted. I wonder how easily this can be fitted to the Cowley or Oxford...

All of these cars came out with cross-ply tyres as standard equipment. However they drive a treat on radial tyres, but you must have the front steering geometry re-set for best effect and tyre life. Also, try to find tyres with a side-wall as close to the original crossplies as possible. This is to keep the gearing about the same.
On standard rims the Oxford and Cowley take:

• 165x15

• 185x15