think this one has been done before elsewhere (worth a search ) but:
Front susp
Check out the camber controlling nuts on the top wishbone, make sure they're tight.
Check that your rack isn't allowing movement of the front wheels for no steering input
Check the wheel bearings aren't loose, check your tyre pressures all round.
You don't say whether it feels loose when driving in a straight line (feathered throttle) -you may be tramlining - are you on cross plies perhaps? Or are you under power/braking - your tracking could be readdressed: If your tracking is toeing out the car is likely to wander in a straight line but turn into corners very well, toe the tracking in and it'll feel more settled on the mway at the expense of initial turn in (I personally don't like the car toed out).
Rear susp
Keep your trailing arms where they are (low works best). You may feel the rear being twitchy but it can actually come from the front.
Get a screwdriver between the central dedion-A frame lug and lever it about, it should take some effort to move the A frame away from the the tube unless your bearing is perished.
Check dampers are both ok (not leaking etc).
If you've a rear anti roll bar I'd disconnect it esp. in winter as it loses grip at the rear IMHO and I'd second the comment that your springs are too hard for the road.
Nigel Mills - My next car must have xenons